1 literature reference for Vipera berus nikolskii JOGER 1997:

Author: Joger,U., Lenk,P., Baran,I., Böhme,W., Ziegler,T., Heidrich,P. & M. Wink
Year: 1997
Title: The phylogenetic position of Vipera barani and of Vipera nikolskii within the Vipera berus complex.
Source: In: Böhme,W. Bisschoff,W. & T. Ziegler (eds.) Herpetologia Bonnensis. Bonn: 185-194.