@article{ref1,
title="Maintaining physical fitness aboard ships",
journal="Nederlands Tijdschrift voor Geneeskunde",
year="1970",
author="Rijsdorp, K.",
volume="114",
number="1",
pages="43-44",
abstract="<p>[Abstract unavailable]</p><p>Language: nl</p>",
language="nl",
issn="0028-2162",
doi="",
url="http://dx.doi.org/"
}