@article{ref1,
title="Engagement in pleasant activities and depression level",
journal="Journal of abnormal psychology",
year="1975",
author="Lewinsohn, P. M.",
volume="84",
number="6",
pages="729-731",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0021-843X",
doi="",
url="http://dx.doi.org/"
}