Supposedly, the check was invented by the Knights Templar between 1100 and 1300 AD—at least that's the official story of the check's invention. But is it true? In the 951th century, an Arab geographer, Ibn Haukal, visited the Ghana Empire in XNUMX AD and wrote about a fact that, for him, was unprecedented.

He commented that he had seen a check for 42.000 gold dinars sent to a merchant in the city of Audoghast by his partner in Sijilmassa, Morocco, which means that the first checks were invented in Africa and not in Europe. ¹Ibn-Hawqal, the Cheque, and Awdaghost. Levtzion, Nehemia. [ed.] Cambridge University Press. 2, sl: The Journal of African History, 1968, Vol. 9, pp. 223-233., as told in the “official story”.

O Empire of Ghana, was one of the largest African empires, emerging around 300 AD and reaching its peak in the 10th and 11th centuries, becoming a superstate. At its height, it controlled vast territories that are now the nations of Senegal, Gambia, Mauritania, Mali, and Guinea.

The empire was located between two rivers, the Senegal and the Niger, and its capital was Kumbi-Saleh, located in what is now southeastern Mauritania. Other important cities were Nema, Audoghast, and Walata.

Due to its vastness, it was necessary to develop a system of control over the money, different from the traditional transportation of physical money, to prevent merchants from being robbed during their long journeys, hence the innovation of the invention of the check. ²Introduction to Various African Kingdoms: Ancient Ghana. DOORS, Understanding Slavery Initiative. [Online] [Citation: February 11, 2021.] http://www.understandingslavery.com/index.php-option=com_content&view=article&id=377&Itemid=232.html..

The first 365-day calendar, similar to the Gregorian calendar (our calendar), was invented by the Egyptians several thousand years before our time. It was a solar calendar with a 365-day year. The year was divided into three 120-day seasons, with each season divided into four 30-day months, plus an additional five-day intercalary period.

These twelve months were initially counted within each season, but they also came to be known by the names of their main festivals. Each month was divided into three 10-day periods, known as decans.

Because the year in this calendar was almost a quarter of a day shorter than the solar year, the Egyptian calendar lost about a day every four years compared to the Gregorian calendar. Therefore, it is sometimes referred to as the wandering year (Latin: annus vagus), as its months rotated about one day in the solar year every four years.

The Canopus Decree of Ptolemy III attempted to correct this by introducing a sixth day every four years, but the proposal was rejected by the Egyptian priests and people and abandoned until the establishment of the Alexandrian or Coptic calendar by Augustus.

The introduction of a leap day into the Egyptian calendar made it equivalent to the reformed Julian calendar, although by extension it continued to diverge from the Gregorian calendar over the course of most centuries. ³Editors of Encyclopaedia Britannica. Egyptian calendar: ancient Egypt. Britannica. [Online] [Citation: February 12, 2021.] https://www.britannica.com/science/Egyptian-calendar..

The Nile River is 7.088 km long from its source in Rwanda's Nyungwe National Park to its mouth in Egypt, making it, until proven otherwise, the longest river in the world. ⁴S. Liu, P. Lu, D. Liu, P. Jin & W. Wang. Pinpointing the sources and measuring the lengths of the main rivers of the world. International Journal of Digital Earth. [Online] March 17, 2009. [Citation: February 12, 2021.] https://www.tandfonline.com/doi/abs/10.1080/17538940902746082..

Located in northeastern Africa, its source is south of the equator and its mouth is north. The river basin covers an area of 3.349.000 km², encompassing Uganda, Tanzania, Rwanda, Kenya, the Democratic Republic of the Congo, Burundi, Sudan, South Sudan, Ethiopia, and Egypt. ⁵Oloo, Adams. The Quest for Cooperation in the Nile Water Conflicts: A Case for Eritrea. 2007..

It is formed by the confluence of three other rivers: the White Nile (Bahr-el-Abiad), the Blue Nile (Bahr-el-Azrak), and the Atbara River. The Blue Nile (Bahr-el-Azrak) rises in Lake Tana in Ethiopia, converging with the White Nile in Khartoum, the capital of Sudan.

The Cubango Delta, also called the Okavango Delta, is the largest inland delta in the world. ⁶Seven Natural Wonders of Africaa. Okavango delta. Seven Natural Wonders of Africa. [Online] 2021. [Citation: February 12, 2021.] http://sevennaturalwonders.org/africa/okavango-delta-2/., is formed where the Cubango River reaches a tectonic valley located at an altitude of 930-1.000 meters in the central part of the Kalahari endorheic basin, in Botswana. ⁷Ramsar.org. Ramsar Information Sheet. sl: Ramsar.org, 1996. BW879RISformer.pdf. Extract from: Okavango, Delta System – https://rsis.ramsar.org/ris/879.. All the water that reaches the delta evaporates and does not flow into any sea or ocean.

Each year approximately 11 cubic kilometers of water spread over an area of 6.000-15.000 km2, part of this water is drained into Lake Ngami ⁸Dr. Cecil Keen. Okavango. Greatest Places Physical Geography. [Online] July 1997. [Citation: February 12, 2021.] https://www.greatestplaces.org/notes/okavango.htm.. The Delta area was once part of Lake Makgadikgadi, an ancient lake that nearly dried up in the early Holocene. ⁹On the geological time scale, the Holocene is the current warm period, known as MIS1, which began approximately 11,650 years ago. ¹⁰The great inland deltas of Africa. panels, S. McCarthy, Author links open overlay. 3, 1993, Journal of African Earth Sciences (and the Middle East), Vol.The Cubango Delta is one of the Seven Wonders of Africa ¹¹Seven Natural Wonders of Africaa. Okavango delta. Seven Natural Wonders of Africa. [Online] 2021. [Citation: February 12, 2021.] http://sevennaturalwonders.org/africa/okavango-delta-2/..

The Blyde River Canyon is a 26-km-long canyon located in South Africa's Mpumalanga region. It is the third-largest canyon in the world, behind the Grand Canyon in the United States and the Fish River Canyon in Namibia.

In contrast to these canyons, which are essentially rocky, the Blyde River Canyon is considered a "green canyon" due to its lush subtropical foliage. Its extremely steep cliffs reach an average depth of 800 meters, making it the steepest canyon in the world. ¹²Mpumalanga. Blyde River Cnyon Nature Reserve. Mpumalanga. [Online] [Citation: February 12, 2021.] http://www.mpumalanga.com/our-provincial-parks/blyde-river-canyon-nature-reserve..

The Sahara (الصحراء الكبرى), whose name comes from the Arabic word ṣaḥrāʾ, which, for some unknown reason, means “desert” ¹³Wehr, Hans. A Dictionary of Modern Written Arabic (Arabic-English). [ed.] Otto Harrassowitz. 4th. Wiesbaden: sn, 1994. p. 589., is the largest hot desert in the world, surpassed only in size by the cold deserts of Antarctica and the Arctic ¹⁴Kerry H. Cook, Edward K. Vizy. Detection and Analysis of an Amplified Warming of the Sahara Desert. Journal of Climate. [Online] August 15, 2015. [Citation: February 12, 2021.] https://doi.org/10.1175/JCLI-D-14-00230.1.It is one of the most hostile environments on Earth, covering an area of 9,4 million square kilometers, making up almost a third of the African continent. ¹⁵Arthur N. Strahler, Alan H. Strahler. Modern Physical Geography. 3rd. New York: John Wiley & Sons, 1987..

The Sahara is made up of a huge variety of topographical features, but the most famous is undoubtedly its sand dune fields, often featured in numerous films. The dunes can reach almost 183 meters in height, yet they cover only about 15% of the entire desert.

Other topographic features include mountains, plateaus, sand and gravel plains, salt flats, basins, and depressions. Mount Koussi, an extinct volcano in Chad, is the highest point in the Sahara at 3.415 meters, and the Qattara Depression in Egypt is the deepest point in the Sahara, lying 133 meters below sea level. ¹⁶Arthur N. Strahler, Alan H. Strahler. Modern Physical Geography. 3rd. New York: John Wiley & Sons, 1987..

Mount Kilimanjaro is located in Tanzania and is one of the Big Seven (the highest peaks on the seven continents). It is also the highest mountain in Africa and the highest free-standing mountain. ¹⁷A freestanding mountain is a mountain that stands completely alone and is not part of any mountain range. Traditionally, these are volcanoes that ruptured the Earth's crust and formed from the accumulation of several layers of hardened volcanic ash, lava, pumice, and tephra—fragmented material that is the fallout from a volcanic eruption. in the world.

It is a dormant stratovolcano, composed of three distinct volcanic cones: Kibo, which is the highest, located on the rim of its crater, Uhuru Peak, which rises to 5.895 meters above sea level, and Mawenzi, which rises to 5.149 meters. ¹⁸Corrado Casinov, Terrill Thompson. Mawenzi. Peakware – World Mountain Encyclopedia. [Online] [Citation: February 13, 2021.] http://www.peakware.com/peaks.html?pk=2084. and Shira, which is the lowest, at 4.005 meters ¹⁹Nicolas J. Cullen, Thomas Mölg, Georg Kaser, Khalid Hussein, Konrad Steffen, Douglas R. Hardy. Kilimanjaro Glaciers: Recent areal extent from satellite data and new interpretation of observed 20th century retreat rates. Geophysical Research Letters. August 31, 2006, Vol. 33, 16.. The Mawenzi and Shira cones are extinct, however Kibo is dormant and may erupt again. ²⁰Philippe Nonnotte, Hervé Guillou, Bernard Le Gall, Mathieu Benoit, Joseph Cotten, Stéphane Scaillet. New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa. Journal of Volcanology and Geothermal Research. 2008..

The origin of the name Kilimanjaro is uncertain, so there are several theories about its meaning and origin. The most widely accepted is that the name derives from a combination of the Swahili word Kilima, meaning "small mountain," and the word KiChagga Njaro, loosely translated as "whiteness," meaning "small white mountain."

Supposedly it would be an affectionate name given to the mountain, since this ancient volcano has a snow-covered top and rises in the middle of the savannah. ²¹A Savanna is a vegetation formation characteristic of the plains of humid tropical or subtropical regions, where tall herbaceous plants grow, with some scattered shrubs and trees., offering a unique spectacle to those who see it ²²Hutchinson, J.A. The Meaning of Kilimanjaro. [ed.] Tanganyika Notes and Records. 1965, 64..

The Goliath frog (Conraua goliath) is an African amphibian that can measure up to 40 cm and weigh up to 3 kg, making it the largest frog in the world. Its jumping ability is remarkable, capable of leaping up to 3 meters in a single bound; however, it tires quickly after two or three leaps.

They live in rivers close to rapid flows with sandy bottoms and very dense and extremely humid areas, with relatively high temperatures, in Central African countries, more precisely, between Equatorial Guinea and Cameroon. ²³Contribution to the biology of the Giant Frog (Conraua goliath, Boulenger). Sabater-Pi, Jordi. 2, 1985, Amphibia-Reptilia, Vol.. Unfortunately, it is on the verge of extinction due to the destruction of its habitat and hunting for commercialization as a pet. ²⁴What is the biggest frog in the world? Strange World Writing. April 18, 2011, Super Interesting..

The largest, tallest, and fastest land animals in the world are African. They are, respectively, the African elephant, the giraffe, and the cheetah. And, although not included in the title, the largest and also the fastest bird on the planet, and the one that lays the largest eggs, is African, and it is none other than our very interesting ostrich...

The African elephant (Loxodonta) is a genus in the Elephantidae family. The genus consists of two extant species of elephant: the savanna elephant (Loxodonta africana) and the forest elephant (Loxodonta cyclotis). Unfortunately, both species are classified on the IUCN Red List. ²⁵The IUCN Red List, created in 1964, is one of the world's most detailed inventories of the global conservation status of various species of plants, animals, fungi, and protoctists. The Red List uses precise criteria to assess the extinction risk of thousands of species and subspecies, relevant to all species and in all regions of the world. It aims to inform the public and policymakers about the urgency of conservation measures, as well as assist the international community in reducing extinctions. as vulnerable ²⁶Blanc, J. Loxodonta africana. sl: The IUCN Red List of Threatened Species, 2008..

The male savanna elephant reaches an average height of 3,2 meters and weighs 6 tons, making it the largest land animal in existence. The largest specimen ever recorded weighed approximately 12.3 tons. ²⁷Loxodonta africana. Larry Laursen, Marc Bekoff. 92, sl: The American Society of Mammalogists, January 5, 1978, Mammalian Species..

The giraffe (Giraffa) is an African artiodactyl mammal, the tallest land animal, and the largest terrestrial ruminant. Until 2001, only one species of giraffe was recognized. Currently, after further study, nine living giraffe species are recognized.

1. Kordofan giraffe (Giraffa camelopardalis antiquorum).
2. Nubian giraffe (Giraffa camelopardalis camelopardalis).
3. Rothschild's giraffe (Giraffa camelopardalis rothschildi).
4. West African giraffe (Giraffa camelopardalis peralta), also known as Niger giraffe or Nigerian giraffe.
5. Reticulated Giraffe (Giraffa camelopardalis reticulata), also known as Somali Giraffe.
6. Angolan giraffe (Giraffa camelopardalis angolensis).
7. South African giraffe (giraffa camelopardalis giraffa), also known as Cape giraffe.
8. Masai giraffe (Giraffa camelopardalis tippelskirchi), also known as Kilimanjaro giraffe.
9. Thornicroft's giraffe (Giraffa camelopardalis thornicrofti), better known as the Rhodesian giraffe.

In addition to these nine species, seven other species of giraffes are still recognized, however they are extinct. ²⁸Colin Groves, Peter Grubb. Ungulate Taxonomy. sl : JHU Press, 2011..

The cheetah (Acinonyx jubatus) is a member of the Felidae family, though its behavior is atypical compared to other members of the same family. It is the only living species of the genus Acinonyx and lives in the African savanna.

It is a predatory animal, preferring a simple strategy: hunting its prey through high-speed pursuits, rather than tactics such as ambush or group hunting.

It can reach speeds of up to 115 km/h, for short periods at a time (up to 500 meters of running) and is the fastest known land animal. ²⁹Claw retraction and protraction in the Carnivora: the cheetah (Acinonyx jubatus) as an atypical felid. Anthony P. Russell, Harold N. Bryant. 2006, Journal of Zoology. ³⁰Doherty, James G. Speed of Animals. [ed.] The American Museum of Natural History. Natural History Magazine. March 1974..

The Ostrich (Struthio camelus) ³¹There are those who claim that the name “Avestruz” is a gender noun, as such, the article must agree with the sex of the animal, therefore it should be said “o avestruz” and not “a avestruz”, however, consulting the website “Ciberdúvidas” the only recognized website for clarifying doubts regarding the Portuguese language, we found that they claim that “Avestruz pode ter dois dois gêneros” as such it is correct to use both forms. ³²Fonseca, F.V. Peixoto da. The ostrich genus. Cyberquestions of the Portuguese Language. [Online] December 10, 2007. [Citation: February 12, 2021.] https://ciberduvidas.iscte-iul.pt/consultorio/perguntas/o-genero-de-avestruz/22239. is a flightless bird native to Africa. It is one of only two living species in the family Struthionidae, genus Struthio, and order Struthioniformes, along with the Somali ostrich (Struthio molybdophanes), which was recognized as a separate species in 2014. ³³Bird Life International. Struthio molybdophanes. sl: The IUCN Red List of Threatened Species, 2016..

The common ostrich is considered the largest living bird species, weighing up to 150 kg. ³⁴Davies, SJJF Birds I Tinamous and Ratites to Hoatzins. [book author] Michael Hutchins. Grzimek's Animal Life Encyclopedia. 2nd. sl: Farmington Hills, MI: Gale Group, 2003, Vol. 8., the fastest, reaching speeds of up to 80 km/h ³⁵Doherty, James G. Speed of Animals. [ed.] The American Museum of Natural History. Natural History Magazine. March 1974., also being the bird that lays the largest and heaviest eggs, between 1,2 kg and 1,8 kg ³⁶Hyde, Kenneth. Zoology: An Inside View of Animals. 3rd. Dubuque, IA: Kendall Hunt Publishing, 2004. p. 475..

Lake Nyassa is home to the largest variety of fish species in the world. ³⁷World Heritage Sites. Malawi. World Heritage Sites. [Online] [Citation: February 13, 2021.] https://web.archive.org/web/20080511101010/http://www.unep-wcmc.org/protected_areas/data/wh/lakemal.html., including at least 700 species of cichlids ³⁸How many species of cichlid fish are there in African lakes? GF Turner, O Seehausen, ME Knight, CJ Allender, RL Robinson. 3, 2008 July 2008, Molecular Ecology, Vol. 10.. It is one of the African Great Lakes and the southernmost of the East African Rift system and is located between Mozambique, Malawi and Tanzania.

It is the fifth largest freshwater lake in the world by volume, the ninth largest lake in the world by area, the second deepest lake in the world, and the third largest in Africa. The Mozambican government officially declared the lake a reserve on June 10, 2011. ³⁹Mozambique's Lake Niassa declared a reserve and Ramsar site. WWF. June 10, 2011, WWF..

Lake Nyassa is a meromictic lake, meaning its water layers do not mix. The permanent stratification of Lake Niassa's water and the oxide-anoxic boundary (related to oxygen in the water) are maintained by moderately small chemical and thermal gradients. ⁴⁰Seasonal and Interannual Particle Export in an African Rift Valley Lake: A 5-Yr Record from Lake Malawi, Southern East Africa. Pilskaln, Cynthia H. 4, July 19, 2004, Limnology and Oceanography, Vol. 49, pp. 964–977..

Notes and Bibliography

1. Ibn-Hawqal, the Cheque, and Awdaghost. Levtzion, Nehemia. [ed.] Cambridge University Press. 2, sl: The Journal of African History, 1968, Vol. 9, pp. 223-233.
2. Introduction to Various African Kingdoms: Ancient Ghana. DOORS, Understanding Slavery Initiative. [Online] [Citation: February 11, 2021.] http://www.understandingslavery.com/index.php-option=com_content&view=article&id=377&Itemid=232.html.
3. Editors of Encyclopaedia Britannica. Egyptian calendar: ancient Egypt. Britannica. [Online] [Citation: February 12, 2021.] https://www.britannica.com/science/Egyptian-calendar.
4. S. Liu, P. Lu, D. Liu, P. Jin & W. Wang. Pinpointing the sources and measuring the lengths of the main rivers of the world. International Journal of Digital Earth. [Online] March 17, 2009. [Citation: February 12, 2021.] https://www.tandfonline.com/doi/abs/10.1080/17538940902746082.
5. Oloo, Adams. The Quest for Cooperation in the Nile Water Conflicts: A Case for Eritrea. 2007.
6. Seven Natural Wonders of Africaa. Okavango delta. Seven Natural Wonders of Africa. [Online] 2021. [Citation: February 12, 2021.] http://sevennaturalwonders.org/africa/okavango-delta-2/.
7. Ramsar.org. Ramsar Information Sheet. sl: Ramsar.org, 1996. BW879RISformer.pdf. Extract from: Okavango ,Delta System – https://rsis.ramsar.org/ris/879.
8. Dr. Cecil Keen. Okavango. Greatest Places Physical Geography. [Online] July 1997. [Citation: February 12, 2021.] https://www.greatestplaces.org/notes/okavango.htm.
9. On the geological time scale, the Holocene is the current warm period, known as MIS1, which began approximately 11,650 years ago.
10. The great inland deltas of Africa. panels, S. McCarthy, Author links open overlay. 3, 1993, Journal of African Earth Sciences (and the Middle East), Vol.
11. Mpumalanga. Blyde River Cnyon Nature Reserve. Mpumalanga. [Online] [Citation: February 12, 2021.] http://www.mpumalanga.com/our-provincial-parks/blyde-river-canyon-nature-reserve.
12. Wehr, Hans. A Dictionary of Modern Written Arabic (Arabic-English). [ed.] Otto Harrassowitz. 4th. Wiesbaden: sn, 1994. p. 589.
13. Kerry H. Cook, Edward K. Vizy. Detection and Analysis of an Amplified Warming of the Sahara Desert. Journal of Climate. [Online] August 15, 2015. [Citation: February 12, 2021.] https://doi.org/10.1175/JCLI-D-14-00230.1.
14. Arthur N. Strahler, Alan H. Strahler. Modern Physical Geography. 3rd. New York: John Wiley & Sons, 1987.
15. A freestanding mountain is a mountain that stands completely alone and is not part of any mountain range. Traditionally, these are volcanoes that ruptured the Earth's crust and formed from the accumulation of several layers of hardened volcanic ash, lava, pumice, and tephra—fragmented material that is the fallout from a volcanic eruption.
16. Corrado Casinov, Terrill Thompson. Mawenzi. Peakware – World Mountain Encyclopedia. [Online] [Citation: February 13, 2021.] http://www.peakware.com/peaks.html?pk=2084.
17. Nicolas J. Cullen, Thomas Mölg, Georg Kaser, Khalid Hussein, Konrad Steffen, Douglas R. Hardy. Kilimanjaro Glaciers: Recent areal extent from satellite data and new interpretation of observed 20th century retreat rates. Geophysical Research Letters. August 31, 2006, Vol. 33, 16.
18. Philippe Nonnotte, Hervé Guillou, Bernard Le Gall, Mathieu Benoit, Joseph Cotten, Stéphane Scaillet. New K–Ar age determinations of Kilimanjaro volcano in the North Tanzanian diverging rift, East Africa. Journal of Volcanology and Geothermal Research. 2008.
19. A Savanna is a vegetation formation characteristic of the plains of humid tropical or subtropical regions, where tall herbaceous plants grow, with some scattered shrubs and trees.
20. Hutchinson, J. A. The Meaning of Kilimanjaro. [ed.] Tanganyika Notes and Records. 1965, 64.
21. Contribution to the biology of the Giant Frog (Conraua goliath, Boulenger). Sabater-Pi, Jordi. 2, 1985, Amphibia-Reptilia, Vol.
22. What is the biggest frog in the world? Strange World Writing. April 18, 2011, Super Interesting.
23. The IUCN Red List, created in 1964, is one of the world's most detailed inventories of the global conservation status of various species of plants, animals, fungi, and protoctists. The Red List uses precise criteria to assess the extinction risk of thousands of species and subspecies, relevant to all species and in all regions of the world. It aims to inform the public and policymakers about the urgency of conservation measures, as well as assist the international community in reducing extinctions.
24. Blanc, J. Loxodonta africana. sl: The IUCN Red List of Threatened Species, 2008.
25. Loxodonta africana. Larry Laursen, Marc Bekoff. 92, sl: The American Society of Mammalogists, January 5, 1978, Mammalian Species.
26. Colin Groves, Peter Grubb. Ungulate Taxonomy. sl : JHU Press, 2011.
27. Claw retraction and protraction in the Carnivora: the cheetah (Acinonyx jubatus) as an atypical felid. Anthony P. Russell, Harold N. Bryant. 2006, Journal of Zoology.
28. Doherty, James G. Speed of Animals. [ed.] The American Museum of Natural History. Natural History Magazine. March 1974.
29. There are those who claim that the name “Avestruz” is a gendered noun, as such, the article must agree with the sex of the animal, therefore it should be said “o avestruz” and not “a avestruz”, however, consulting the website “Ciberdúvidas” the only recognized website for clarifying doubts regarding the Portuguese language, we found that they claim that “Avestruz pode ter dois dois gêneros” and as such it is correct to use both forms.
30. Fonseca, F.V. Peixoto da. The genus of ostrich. Cyber-doubts about the Portuguese Language. [Online] December 10, 2007. [Citation: February 12, 2021.] https://ciberduvidas.iscte-iul.pt/consultorio/perguntas/o-genero-de-avestruz/22239.
31. Bird Life International. Struthio molybdophanes. sl: The IUCN Red List of Threatened Species, 2016.
32. Davies, SJJF. Birds I Tinamous and Ratites to Hoatzins. [book author] Michael Hutchins. Grzimek's Animal Life Encyclopedia. 2nd. sl: Farmington Hills, MI: Gale Group, 2003, Vol. 8.
33. Hyde, Kenneth. Zoology: An Inside View of Animals. 3rd. Dubuque, IA: Kendall Hunt Publishing, 2004. p. 475.
34. World Heritage Sites. Malawi. World Heritage Sites. [Online] [Citation: February 13, 2021.] https://web.archive.org/web/20080511101010/http://www.unep-wcmc.org/protected_areas/data/wh/lakemal.html.
35. How many species of cichlid fish are there in African lakes? GF Turner, O Seehausen, ME Knight, CJ Allender, RL Robinson. 3, 2008 July 2008, Molecular Ecology, Vol. 10.
36. Mozambique's Lake Niassa declared a reserve and Ramsar site. WWF. June 10, 2011, WWF.
37. Seasonal and Interannual Particle Export in an African Rift Valley Lake: A 5-Yr Record from Lake Malawi, Southern East Africa. Pilskaln, Cynthia H. 4, July 19, 2004, Limnology and Oceanography, Vol. 49, pp. 964–977.