@article{ref1,
title="Many manoeuvres with yo yos can be dangerous to teeth",
journal="British medical journal: BMJ",
year="1999",
author="Cooper, W. and Cooper, E. and Cooper, G.",
volume="318",
number="7190",
pages="1078-1078",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0959-8138",
doi="",
url="http://dx.doi.org/"
}