@article{ref1,
title="Advances lead to tougher, more durable hard hat",
journal="Occupational health and safety",
year="1991",
author="Bross, M. S.",
volume="60",
number="2",
pages="22-23",
abstract="Abstract unavailable.",
language="",
issn="0362-4064",
doi="",
url="http://dx.doi.org/"
}