Middendorf III, G.A.; Sherbrooke, W.C.; Braun, E.J. (2001). "Comparison of Blood Squirted from the Circumorbital Sinus and Systemic Blood in a Horned Lizard, Phrynosoma cornutum". The Southwestern Naturalist. 46 (3): 384–387. doi:10.2307/3672440. JSTOR3672440.
Middendorf III, G.A.; Sherbrooke, W.C.; Braun, E.J. (2001). "Comparison of Blood Squirted from the Circumorbital Sinus and Systemic Blood in a Horned Lizard, Phrynosoma cornutum". The Southwestern Naturalist. 46 (3): 384–387. doi:10.2307/3672440. JSTOR3672440.
Pianka, Eric; Hodges, Wendy. "Horned Lizards, Part 2". uts.cc.utexas.edu. University of Texas. Archived from the original on April 26, 2015. Retrieved March 1, 2015.
Pianka, Eric; Hodges, Wendy. "Horned Lizards, Part 2". uts.cc.utexas.edu. University of Texas. Archived from the original on April 26, 2015. Retrieved March 1, 2015.