@article{ref1,
title="Factors in the design of protective helmets",
journal="Aerospace medicine",
year="1969",
author="Rayne, J. M. and Maslen, K. R.",
volume="40",
number="6",
pages="631-637",
abstract="Abstract unavailable.",
language="",
issn="0001-9402",
doi="",
url="http://dx.doi.org/"
}