@article{ref1,
title="Internal-external control and social reinforcement effects on motor performance",
journal="Research quarterly",
year="1971",
author="Martens, R.",
volume="42",
number="3",
pages="307-313",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0034-5377",
doi="",
url="http://dx.doi.org/"
}