@article{ref1,
title="Study of hypertension in urban bus drivers questioned. Study design as source of bias",
journal="American journal of public health",
year="1993",
author="Li, Guohua",
volume="83",
number="4",
pages="600-601",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0090-0036",
doi="",
url="http://dx.doi.org/"
}