@article{ref1,
title="Variation of visual perception of spatial objects and development of perceptual aptitude",
journal="Nippon Ganka Gakkai Zasshi",
year="1971",
author="Suzumura, A.",
volume="75",
number="9",
pages="1974-2006",
abstract="<p>[Abstract unavailable]</p><p>Language: ja</p>",
language="ja",
issn="0029-0203",
doi="",
url="http://dx.doi.org/"
}