@article{ref1,
title="Structural analysis of smoking, alcohol use, and personality factors in MZ and DZ twin pair relationships",
journal="Progress in clinical and biological research",
year="1981",
author="Langinvainio, H. and Kaprio, Jaakko A. and Koskenvuo, Karoliina and Tarkkonen, L.",
volume="69",
number="C",
pages="23-35",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0361-7742",
doi="",
url="http://dx.doi.org/"
}