@article{ref1,
title="Suicide in twins and only children",
journal="American journal of human genetics",
year="1949",
author="Kallmann, F. J. and De Porte, J. and De Porte, E. and Feingold, L.",
volume="1",
number="2",
pages="113-126",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0002-9297",
doi="",
url="http://dx.doi.org/"
}