@article{ref1,
title="An approach to the problem of progressive failure: discussion",
journal="Canadian geotechnical journal",
year="1973",
author="Mitchell, R. J. and Lawrence, V. M.",
volume="10",
number="3",
pages="562-564",
abstract="<p>[Abstract unavailable]</p><p>Language: en</p>",
language="en",
issn="0008-3674",
doi="10.1139/t73-049",
url="http://dx.doi.org/10.1139/t73-049"
}