Irwin-Williams, C.; et al. (1969). "Comments on the Associations of Archaeological Materials and Extinct Fauna in the Valsequillo Region Puebla Mexico". American Antiquity. 34 (1): 82–83. doi:10.2307/278319. JSTOR278319. S2CID163834117.
Irwin-Williams, C.; et al. (1969). "Comments on the Associations of Archaeological Materials and Extinct Fauna in the Valsequillo Region Puebla Mexico". American Antiquity. 34 (1): 82–83. doi:10.2307/278319. JSTOR278319. S2CID163834117.
Irwin-Williams, C.; et al. (1969). "Comments on the Associations of Archaeological Materials and Extinct Fauna in the Valsequillo Region Puebla Mexico". American Antiquity. 34 (1): 82–83. doi:10.2307/278319. JSTOR278319. S2CID163834117.