@article{ref1,
title="Definition and uses of the concept "isomorphism"",
journal="Perceptual and motor skills",
year="1959",
author="Johnson, H. M.",
volume="9",
number="1",
pages="12-14",
abstract="<p>[Abstract unavailable]</p>",
language="en",
issn="0031-5125",
doi="10.2466/pms.1959.9.g.12",
url="http://dx.doi.org/10.2466/pms.1959.9.g.12"
}