@article{ref1,
title="Conservation across illusory transformations in young children",
journal="Acta psychologica",
year="1966",
author="Elkind, D.",
volume="25",
number="4",
pages="389-400",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0001-6918",
doi="",
url="http://dx.doi.org/"
}