@article{ref1,
title="Experimental studies of shift-work. 3. stabilized 12-hour shift system",
journal="Ergonomics",
year="1969",
author="Colquhoun, W. P. and Blake, M. J. and Edwards, R. S.",
volume="12",
number="6",
pages="865-882",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0014-0139",
doi="",
url="http://dx.doi.org/"
}