@article{ref1,
title="Epidemiology of primary osteoporosis in China",
journal="Osteoporosis international",
year="1997",
author="Liu, Z. H. and Zhao, Y. L. and Ding, G. Z. and Zhou, Y.",
volume="7",
number="Suppl 3",
pages="S84-7",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0937-941X",
doi="",
url="http://dx.doi.org/"
}