↑ 12Berta, A.; Churchill, M. & Boessenecker, R.W. (2018). "The Origin and Evolutionary Biology of Pinnipeds: Seals, Sea Lions, and Walruses". Annual Review of Earth and Planetary Sciences. 46: 203—228. Bibcode:2018AREPS..46..203B. doi:10.1146/annurev-earth-082517-010009.
↑ 12Mitchell, E. & Tedford, R. H. (1973). "The Enaliarctinae: a new group of extinct aquatic Carnivora and a consideration of the origin of the Otariidae". Bulletin of the AMNH. 151 (3). hdl:2246/1178.
↑McKenna, Malcolm C., and Susan K. Bell (1997). Classification of Mammals Above the Species Level. New York: Columbia University Press. 631 pp. ISBN 0-231-11013-8