Campbell, J.; J. Vannini (1988). "A new subspecies of beaded lizard, Heloderma horridum, from the Motagua Valley of Guatemala". Journal of Herpetology. 22 (4): 457–468. doi:10.2307/1564340. JSTOR1564340.
Pianka, Eric (1966). "Convexity, desert lizards and spatial heterogeneity". Ecology. 47 (6): 1055–1059. doi:10.2307/1935656. JSTOR1935656.
Campbell, J.; J. Vannini (1988). "A new subspecies of beaded lizard, Heloderma horridum, from the Motagua Valley of Guatemala". Journal of Herpetology. 22 (4): 457–468. doi:10.2307/1564340. JSTOR1564340.
Pianka, Eric (1966). "Convexity, desert lizards and spatial heterogeneity". Ecology. 47 (6): 1055–1059. doi:10.2307/1935656. JSTOR1935656.