Hernández-Hernández, Julio César, et al. “Diet Selectivity in Relation to Food Quality and Availability by the Endemic Perote Squirrel (Xerospermophilus Perotensis)”. THERYA, vol. 9, no. 2, Apr. 2018, p. 121, https://therya.mastozoologiamexicana.com/index.php/THERYA/article/view/553.