@article{ref1,
title="Measurement of free-range activity in children as modified by social and environmental complexity",
journal="American journal of clinical nutrition",
year="1971",
author="Wade, M. G. and Ellis, M. J.",
volume="24",
number="12",
pages="1457-1460",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-9165",
doi="",
url="http://dx.doi.org/"
}