Gerhard Roth und Ursula Dicke. Evolution of the brain and Intelligence. TRENDS in Cognitive Sciences. 2005-05, 9 (5): 250. PMID 15866152. doi:10.1016/j.tics.2005.03.005.使用|accessdate=需要含有|url= (帮助)
Shoshani, Jeheskel; Kupsky, William J.; Marchant, Gary H. Elephant brain Part I: Gross morphology, functions,comparative anatomy, and evolution. Brain Research Bulletin. 30 June 2006, 70 (2): 124–157. PMID 16782503. doi:10.1016/j.brainresbull.2006.03.016.
Gerhard Roth und Ursula Dicke. Evolution of the brain and Intelligence. TRENDS in Cognitive Sciences. 2005-05, 9 (5): 250. PMID 15866152. doi:10.1016/j.tics.2005.03.005.使用|accessdate=需要含有|url= (帮助)
Shoshani, Jeheskel; Kupsky, William J.; Marchant, Gary H. Elephant brain Part I: Gross morphology, functions,comparative anatomy, and evolution. Brain Research Bulletin. 30 June 2006, 70 (2): 124–157. PMID 16782503. doi:10.1016/j.brainresbull.2006.03.016.