@article{ref1,
title="Psychomotor development of twins in the first six months of life",
journal="Acta geneticae medicae et gemellologiae",
year="1974",
author="Chrzanowska, D. and Zdanska-Brincken, M.",
volume="22",
number="Suppl",
pages="129-131",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-5660",
doi="",
url="http://dx.doi.org/"
}