Kadwell, M., M. Fernandez, H. F. Stanley, R. Baldi, J. C. Wheeler, R. Rosadio, and M. W. Bruford 2001-12-22. Proceedings of the Royal Society of London B, vol. 268, no. 1485. . . 2575-2584. . .
Wilson, Don E., and DeeAnn M. Reeder, eds. 1992-01-01. Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed., 3rd printing. Smithsonian Institution Press. Washington, DC, USA. xviii + 1207. 1-56098-217-9. Corrections were made to text at 3rd printing.
Wilson, Don E., and F. Russell Cole 2000-01-01. Common Names of Mammals of the World. Smithsonian Institution Press. Washington, DC, USA. xiv + 204. 1-56098-383-3. With contributions by Bernadette N. Graham, Adam P. Potter, and Mariana M. Upmeyer.
Marín, Juan C., Beatriz Zapata, Benito Gonzàlez, Cristian Bonacic, Jane C. Wheeler, et al. 2007-06-01. Revisita Chlena de Historia Natural, vol. 80. . . 121-140. . .
Donna J. Reynolds, NatureServe: Grubb, in Wilson and Reeder, eds. (2005), lists Lama pacos (Linnaeus, 1758) as a synonym of Lama glama glama (Linnaeus, 1758), but he also mentions pacos in comments under Vicugna vicugna about the systematics of the alpaca. Recent genetic studies (Kadwell et al., 2001; Marín et al., 2007) have demonstrated that the alpaca was derived from Vicugna vicugna