@article{journal,
author = {Nadal, J.},
title = {Observaci{\'o}n de apareamiento en Vipera aspis (L., 1766)},
year = {1988},
volume = {12},
pages = {378--379},
journal = {Miscel·l{\`a}nia Zool{\`o}gica},
keywords = {Vipera aspis, Biology , Mating behaviour}
}