@article{ref1,
title="A motor hypothesis of perceptual development",
journal="American journal of psychology",
year="1953",
author="Siegel, A. I.",
volume="66",
number="2",
pages="301-304",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0002-9556",
doi="",
url="http://dx.doi.org/"
}