Reference

Yehudah L. Werner, Naomi Sivan, Vered Kushnir, Uzi Motro (1999): A Statistical Approach to Variation in Cerastes (Ophidia: Viperidae), with the Description of Two Endemic Subspecies – Kaupia - Darmstädter Beiträge zur Naturgeschichte – 8: 83 - 97.