@article{ref1,
title="Mandatory and directory rules",
journal="Legal studies",
year="1981",
author="Evans, Jim",
volume="1",
number="3",
pages="227-256",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0261-3875",
doi="10.1111/j.1748-121X.1981.tb00122.x",
url="http://dx.doi.org/10.1111/j.1748-121X.1981.tb00122.x"
}