Baird, S. T.
1855. Characteristics of some new species of Mammalia, collected by the U. S. and Mexican Boundary Survey, Major W. H. Emory, U. S. A. Commissioner. Proc. Acad. Nat. Sci. Philadelphia, 7:331-333, April.
1858. Mammals. In General report upon the Zoology of the Several Pacific railroad routes. U. S. P. R. R. Exp. and Surveys, pp. xlviii + 757, 60 pls., July 14.
Baker, R. H.
1951. Mammals from Tamaulipas, México. Univ. Kansas Publ., Mus. Nat. Hist., 5:207-218, December 15.
1956. Mammals of Coahuila, México. Ibid., 9:125-335, 75 figs., June 15.
1958. El futuro de la fauna silvestre en el norte de México. Anal. Inst. Biol., México, 28:349-357, June 14.
Baker, R. H., and Villa R., B.
1960. Distribución geographica y población actuales del lobo gris en México. Ibid., 30:369-374, 1 map, March 31.
Booth, E. S.