@article{ref1,
title="Exercise and sleep behaviour. a questionnaire approach",
journal="Ergonomics",
year="1981",
author="Porter, Jared M. and Horne, James A.",
volume="24",
number="7",
pages="511-521",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0014-0139",
doi="",
url="http://dx.doi.org/"
}