Marín-Leyva, Alejandro H., et al. “Feeding Ecology and Habitat of Late Pleistocene Equus Horses from West-Central Mexico Using Carbon and Oxygen Isotopes Variation”. Revista Mexicana De Ciencias Geológicas, vol. 33, no. 2, May 2017, doi:10.22201/cgeo.20072902e.2016.2.493.