Peter Grubb, "Order Perissodactyla," Mammal Species of the World, (3rd ed.), Volume 1, Don E. Wilson & DeeAnn M. Reeder (ed.), Johns Hopkins University Press, 2005, Pages 629-636.
Mario A. Cozzuol, Camila L. Clozato, Elizete C. Holanda, Flávio H. G. Rodrigues, Samuel Nienow, Benoit de Thoisy, Rodrigo A. F. Redondo, Fabrício R. Santos, "A new species of tapir from the Amazon," Journal of Mammalogy, Volume 94, Issue 6, 2013, Pages 1331-1345.
wikipedia.org
en.wikipedia.org
Tougard, Christelle; Delefosse, Thomas; Hänni, Catherine; Montgelard, Claudine (2001), “Phylogenetic Relationships of the Five Extant Rhinoceros Species (Rhinocerotidae, Perissodactyla) Based on Mitochondrial Cytochrome b and 12S rRNA Genes”, Mol. Phylogenet. Evol.19 (1): 34–44