@article{ref1,
title="Pregnancy and physical fitness",
journal="Duodecim: Laaketieteellinen Aikakauskirja",
year="1973",
author="Erkkola, R.",
volume="89",
number="23",
pages="1552-1557",
abstract="<p>[Abstract unavailable]</p><p>Language: fi</p>",
language="fi",
issn="0012-7183",
doi="",
url="http://dx.doi.org/"
}