• [Wiki] http://en.wikipedia.org/wiki/Circaetus_cinereus.
• [AnAge] https://genomics.senescence.info/species/entry.php?species=Circaetus_cinereus.
• [avibase] https://avibase.bsc-eoc.org/species.jsp?lang=EN&avibaseid=6904D83FD07E202F&sec=lifehistory.
• [OrtaKirw2020] Kemp, A. C. and Marks, J. S. (2020). Brown snake-eagle (Circaetus cinereus), version 1.0. in birds of the world (j. del hoyo, a. elliott, j. sargatal, d. a. christie, and e. de juana, editors). cornell lab of ornithology, ithaca, ny, usa. doi:10.2173/bow.brseag1.01.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.
• [PrinPres1991] Prinzinger, R., A.Preßmar, and Schleucher, E. (1991). Body temperature in birds. Comp. Biochem. Physiol., 99A(4):499--506. doi:10.1016/0300-9629(91)90122-S.
• [Stey1964] Steyn, P. (1964). Observations on the brown snake-eagle Circaetus cinereus. Ostrich, 35(1):22–31. doi:10.1080/00306525.1964.9633830.