@article{ref1,
title="The sleep and performance of shift workers",
journal="Human factors",
year="1982",
author="Drud, M. and Watson, Barry C. and Warren, P. S. and Wilkinson, R. T. and Tilley, A. J.",
volume="24",
number="6",
pages="629-641",
abstract="Abstract unavailable.",
language="",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}