Archaeoceti. A Dictionary of Zoology. Encyclopedia.com. läst 15 augusti 2018.
nih.gov
ncbi.nlm.nih.gov
Gatesy, J., Hayashi, C., Cronin, A., and Arctander, P. (30 juli 1996). ”Evidence from milk casein genes that cetaceans are close relatives of hippopotamid artiodactyls”. Molecular Biology and Evolution "13" (7): ss. 954–963. PMID 8752004.