@article{ref1,
title="The Class as a Psycho-Sociological Unit",
journal="Journal of psychology, The",
year="1943",
author="Pressey, Sidney L. and Hanna, David C.",
volume="16",
number="1",
pages="13-19",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0022-3980",
doi="10.1080/00223980.1943.9917158",
url="http://dx.doi.org/10.1080/00223980.1943.9917158"
}