@article{ref1,
title="The effects of age, sleep deprivation, and altitude on complex performance",
journal="Human factors",
year="1986",
author="Collins, W. E. and Mertens, H. W.",
volume="28",
number="5",
pages="541-551",
abstract="Abstract unavailable.",
language="",
issn="0018-7208",
doi="",
url="http://dx.doi.org/"
}