@article{ref1,
title="Psychological follow-up study of twins from birth to five years",
journal="Acta geneticae medicae et gemellologiae",
year="1976",
author="de Coster, W. and Lerou, J. and Dutoit, C. and de Zutter, M. and Derom, R. and Thiery, M. and Vandierendonck, A.",
volume="25",
number="",
pages="198-212",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-5660",
doi="",
url="http://dx.doi.org/"
}