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Krochmal, Aaron R.; George S. Bakken; Travis J. LaDuc (15. 11. 2004). „Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)”. Journal of Experimental Biology. 207 (Pt 24): 4231—4238. PMID15531644. doi:10.1242/jeb.01278.
Krochmal, Aaron R.; George S. Bakken; Travis J. LaDuc (15. 11. 2004). „Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)”. Journal of Experimental Biology. 207 (Pt 24): 4231—4238. PMID15531644. doi:10.1242/jeb.01278.