@article{ref1,
title="Attention deficit disorder in three pairs of monozygotic twins: a case report",
journal="Journal of the American Academy of Child Psychiatry",
year="1984",
author="Heffron, W. A. and Martin, C. A. and Welsh, R. J.",
volume="23",
number="3",
pages="299-301",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-7138",
doi="",
url="http://dx.doi.org/"
}