• [Wiki] http://en.wikipedia.org/wiki/Pyxicephalus_adspersus.
• [EoL] http://eol.org/pages/330829/overview.
• [AnAge] http://genomics.senescence.info/species/entry.php?species=Pyxicephalus_adspersus.
• [ADW] http://animaldiversity.org/accounts/Pyxicephalus_adspersus/.
• [HayeLich1992] Hayes, T. and Licht, P. (1992). Gonadal involvement in sexual size dimorphism in the African bullfrog (Pyxicephalus adspersus). J. Exp. Zool., 264:130--135.
• [Kooy2010] Kooijman, S. (2010). Dynamic Energy Budget theory for metabolic organisation. Cambridge Univ. Press, Cambridge.