@article{ref1,
title="Effects of perceptual shielding in the development of spatial perspectives",
journal="Child development",
year="1972",
author="Brodzinsky, D. M. and Jackson, J. P. and Overton, W. F.",
volume="43",
number="3",
pages="1041-1046",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0009-3920",
doi="",
url="http://dx.doi.org/"
}