@article{ref1,
title="Prevention levels of occupational risks",
journal="Gaceta Sanitaria",
year="1999",
author="Garcia, A. M.",
volume="13",
number="3",
pages="173-176",
abstract="<p>[Abstract unavailable]</p> <p>Language: es</p>",
language="es",
issn="0213-9111",
doi="",
url="http://dx.doi.org/"
}