1. Mayaux P, Bartholomé E, Fritz S, Belward A. A new land-cover map of Africa for the year 2000. J Biogeogr. 2004;31:861–77.
2. Sayre R, Comer P, Hak J, Josse C, Bow J, Warner H, Larwanou M, Kelbessa E, Bekele T, Kehl H, Amena R, Andriamasimanana R, Ba T, Benson L, Boucher T, Brown M, Cress J, Dassering O, Friesen B, Gachathi F, Houcine S, Keita M, Khamala E, Marangu D, Mokua F, Morou B, Mucina L, Mugisha S, Mwavu E, Rutherford M, Sanou P, Syampungani S, Tomor B, Vall A, Weghe JV, Wangui E, Waruingi L. A new map of standardized terrestrial ecosystems of Africa. Washington DC: Association of American Geographers; 2013.
3. Linder HP, de Klerk HM, Born J, Burgess ND, Fjeldså J, Rahbek C. The partitioning of Africa: statistically defined biogeographical regions in sub-Saharan Africa. J Biogeogr. 2012;39:1189–205.
4. Maslin MA, Trauth MH. Plio-Pleistocene east African pulsed climate variability and its influence on early human evolution. In: Grine FE, Leakey RE, Fleagle JG, editors. The first humans - origins of the genus homo. New York: Springer Verlag; 2009. p. 151–8.
5. Kingston JD, Deino AL, Edgar RK, Hill A. Astronomically forced climate change in the Kenyan Rift Valley 2.7–2.55 Ma: implications for the evolution of early hominin ecosystems. J Hum Evol. 2007;53:487–503.