@article{ref1,
title="Twin similarity for usage of common drugs",
journal="Progress in clinical and biological research",
year="1981",
author="Pedersen, N.",
volume="69",
number="C",
pages="53-59",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0361-7742",
doi="",
url="http://dx.doi.org/"
}