@article{ref1,
title="Effects of comparison level feedback on classroom-related verbal learning performance",
journal="Journal of educational psychology",
year="1972",
author="Snyder, C. R.",
volume="63",
number="5",
pages="493-499",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0022-0663",
doi="",
url="http://dx.doi.org/"
}