@article{ref1,
title="Social reinforcement effects on Block Design performance of organic and nonorganic retarded adults",
journal="American journal of mental deficiency",
year="1972",
author="Roth, G. and McManis, D. L.",
volume="77",
number="2",
pages="181-189",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0002-9351",
doi="",
url="http://dx.doi.org/"
}