@article{ref1,
title="Attachment behavior of one-year-olds as a function of mother vs father, sex of child, session, and toys",
journal="Genetic psychology monographs",
year="1974",
author="Willemsen, E. and Flaherty, D. and Heaton, C. and Ritchey, G.",
volume="90",
number="2 Half",
pages="305-324",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0016-6677",
doi="",
url="http://dx.doi.org/"
}