@article{ref1,
title="Headlight ring retroreflectors",
journal="American journal of optometry and archives of American Academy of Optometry",
year="1967",
author="Allen, Merrill J.",
volume="44",
number="12",
pages="765-768",
abstract="Abstract unavailable.",
language="",
issn="0002-9408",
doi="",
url="http://dx.doi.org/"
}