@article{ref1,
title="Human factor problems in helicopters-research and development",
journal="Proceedings of the Royal Society of Medicine",
year="1976",
author="Allan, J. R.",
volume="69",
number="4",
pages="251-252",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0035-9157",
doi="",
url="http://dx.doi.org/"
}