@article{ref1,
title="Individual Differences in Colour Vision and their Measurement",
journal="Journal of psychology, The",
year="1949",
author="Pickford, R. W.",
volume="27",
number="1",
pages="153-202",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0022-3980",
doi="10.1080/00223980.1949.9915984",
url="http://dx.doi.org/10.1080/00223980.1949.9915984"
}