@article{ref1,
title="The effect of social interaction on activity levels in six- to eight-year-old boys",
journal="Child development",
year="1971",
author="Kaspar, J. C. and Lowenstein, R.",
volume="42",
number="4",
pages="1294-1298",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0009-3920",
doi="",
url="http://dx.doi.org/"
}