^Savage, RJG, & Long, MR. Mammal Evolution: an illustrated guide. New York: Facts on File. 1986: 199. ISBN 0-8160-1194-X.
^Jacobs, Louis L.; Scott, Kathleen Marie. Evolution of Tertiary Mammals of North America: Terrestrial carnivores, ungulates, and ungulatelike mammals. Cambridge University Press. 1998. ISBN 0521355192, 9780521355193.引文使用过时参数coauthors (帮助)