@article{ref1,
title="Certifications in occupational health and safety",
journal="American Industrial Hygiene Association journal",
year="1976",
author="Gamble, J. H.",
volume="37",
number="12",
pages="677-679",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-8894",
doi="",
url="http://dx.doi.org/"
}