@article{ref1,
title="Epidemiology of traumatic dental injuries to primary and permanent teeth in a Danish population sample",
journal="International journal of oral surgery",
year="1972",
author="Andreasen, J. O. and Ravn, J. J.",
volume="1",
number="5",
pages="235-239",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0300-9785",
doi="",
url="http://dx.doi.org/"
}