@article{ref1,
title="Effects of mental practice on the acquisition of motor skills of varied difficulty",
journal="Research quarterly",
year="1969",
author="Phipps, S. J. and Morehouse, C. A.",
volume="40",
number="4",
pages="773-778",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0034-5377",
doi="",
url="http://dx.doi.org/"
}