@article{ref1,
title="Girls manipulate, boys fight: gender differences in aggressiveness during adolescence",
journal="Aggressive behavior",
year="1989",
author="Bjorkqvist, Kaj and Lagerspetz, KMJ and Ketola, R.",
volume="15",
number="1",
pages="41-41",
abstract="<p>[Abstract unavailable]</p>",
language="en",
issn="0096-140X",
doi="",
url="http://dx.doi.org/"
}