@article{ref1,
title="The tattoo as an exoskeletal defense",
journal="Perceptual and motor skills",
year="1964",
author="Hawkins, Roger E. and Popplestone, John A.",
volume="19",
number="2",
pages="500-500",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0031-5125",
doi="10.2466/pms.1964.19.2.500",
url="http://dx.doi.org/10.2466/pms.1964.19.2.500"
}