@article{ref1,
title="The use of guide tubes and plastic covers in testing ophthalmic lenses for impact resistance",
journal="American journal of optometry and physiological optics",
year="1974",
author="Kors, K. and St Helen, R.",
volume="51",
number="12",
pages="969-977",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0093-7002",
doi="",
url="http://dx.doi.org/"
}