Valencia-Herverth, Raúl, Jorge Valencia-Herverth, and Fernando Mendoza Quijano. “Corvus imparatus, primer Registro Para Hidalgo, México”. Huitzil Revista Mexicana de Ornitologí­a 10, no. 1 (January 1, 2009): 15–18. Accessed September 24, 2026. http://www.mexorn.org/index.php/huitzil/article/view/82.