Bonnet, Xavier, Serge Akoka, Richard Shine, and Léandre Pourcelot. 2008. “Disappearance of Eggs During Gestation in a Viviparous Snake (<i>Vipera aspis</I>) Detected Using Non-Invasive Techniques”. Acta Herpetologica 3 (2):129-37. https://doi.org/10.13128/Acta_Herpetol-2679.