@article{ref1,
title="Evolution of aggression and the level of selection controversy",
journal="Aggressive behavior",
year="1980",
author="Fry, DP",
volume="6",
number="1",
pages="69-89",
abstract="<p>[Abstract unavailable]</p>",
language="en",
issn="0096-140X",
doi="",
url="http://dx.doi.org/"
}