Omar Cirilli m.fl. (2023). «The last Plio-Pleistocene hipparions of Western Eurasia. A review with remarks on their taxonomy, paleobiogeography and evolution». Quaternary Science Reviews. 306: 107976. ISSN1873-457X. doi:10.1016/j.quascirev.2023.107976.
H. Machado og L. Avilla (2019). «The diversity of South American Equus: did size really matter?». Frontiers in Ecology and Evolution. 7: 235. ISSN2296-701X. doi:10.3389/fevo.2019.00235.
Omar Cirilli m.fl. (2023). «The last Plio-Pleistocene hipparions of Western Eurasia. A review with remarks on their taxonomy, paleobiogeography and evolution». Quaternary Science Reviews. 306: 107976. ISSN1873-457X. doi:10.1016/j.quascirev.2023.107976.
H. Machado og L. Avilla (2019). «The diversity of South American Equus: did size really matter?». Frontiers in Ecology and Evolution. 7: 235. ISSN2296-701X. doi:10.3389/fevo.2019.00235.