@article{ref1,
title="Aggressive behavior of young children in the absence of an adult",
journal="Child development",
year="1957",
author="Siegel, Alberta Engvall",
volume="28",
number="3",
pages="371-378",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0009-3920",
doi="",
url="http://dx.doi.org/"
}