Waring, George H (2003). Horse Behavior (2nd ed.). New York: Noyes Publications/William Andrew Publishing. p. 9. ISBN978-0-8155-1484-8. Consultado o 6 June 2010.
Hunt, Kathleen. "Horse Evolution"(PDF). Carnegie Mellon University. p. 7. Arquivado dende o orixinal(PDF) o 05 de agosto de 2013. Consultado o 2013-09-15.
Darwin, C. R. (ed. 1840). Fossil Mammalia Part 1 No. 4 of The zoology of the voyage of H.M.S. Beagle. By Richard Owen. London: Smith Elder and Co. p. 108–109
David J. Froehlich (2002). "The systematics and taxonomy of the early Eocene equids (Perissodactyla)". Zoological Journal of the Linnean Society134 (2): 141–256. doi:10.1046/j.1096-3642.2002.00005.x.
MacFadden, B. J. (1976). "Cladistic analysis of primitive equids with notes on other perissodactyls". Syst. Zool.25 (1): 1–14. JSTOR2412774. doi:10.2307/2412774.
Outram, A.K.; Stear, N.A.; Bendrey, R.; Olsen, S.; Kasparov, A.; et al. (2009). "The earliest horse harnessing and milking". Science323 (5919): 1332–1335. PMID19265018. doi:10.1126/science.1168594.
Cai, Dawei; Zhuowei Tang; Lu Han; Camilla F. Speller; Dongya Y. Yang; Xiaolin Ma; Jian'en Cao; Hong Zhu; Hui Zhou (2009). "Ancient DNA provides new insights into the origin of the Chinese domestic horse". Journal of Archaeological Science36 (3): 835–842. doi:10.1016/j.jas.2008.11.006.
Orlando, L.; Ginolhac, A.L.; Zhang, G.; Froese, D.; Albrechtsen, A.; Stiller, M.; et al. (2013). "Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse". Nature499 (7456): 74–78. PMID23803765. doi:10.1038/nature12323.
MacFadden, B. J. (1984). "Systematics and phylogeny of Hipparion, Neohipparion, Nannippus, and Cormohipparion (Mammalia, Equidae) from the Miocene and Pliocene of the New World". Bulletin of the American Museum of Natural History179 (1): 1–195. hdl:2246/997.
MacFadden, B. J. (1976). "Cladistic analysis of primitive equids with notes on other perissodactyls". Syst. Zool.25 (1): 1–14. JSTOR2412774. doi:10.2307/2412774.
Bonnie F. Jacobs, John D. Kingston e Louis L. Jacobs. The Origin of Grass-Dominated Ecosystems. Annals of the Missouri Botanical Garden. Vol. 86, No. 2 (Spring, 1999), pp. 590-643. Published by: Missouri Botanical Garden Press. DOI: 10.2307/2666186 https://www.jstor.org/stable/2666186[2]
Outram, A.K.; Stear, N.A.; Bendrey, R.; Olsen, S.; Kasparov, A.; et al. (2009). "The earliest horse harnessing and milking". Science323 (5919): 1332–1335. PMID19265018. doi:10.1126/science.1168594.
Orlando, L.; Ginolhac, A.L.; Zhang, G.; Froese, D.; Albrechtsen, A.; Stiller, M.; et al. (2013). "Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse". Nature499 (7456): 74–78. PMID23803765. doi:10.1038/nature12323.
Piras, F.M.; Nergadze, S.G.; Poletto, V.; Cerutti, F.; Ryder, O.A.; Leeb, T.; Raimondi, E.; Giulotto, E. (2009). "Phylogeny of Horse Chromosome 5q in the Genus Equus and Centromere Repositioning". Cytogenetic and Genome Research126 (1–2): 165–172. PMID20016166. doi:10.1159/000245916.
Hunt, Kathleen. "Horse Evolution"(PDF). Carnegie Mellon University. p. 7. Arquivado dende o orixinal(PDF) o 05 de agosto de 2013. Consultado o 2013-09-15.