@article{ref1,
title="Hardship and collective violence in France, 1830 to 1960",
journal="American sociological review",
year="1972",
author="Snyder, David and Tilly, Charles",
volume="37",
number="5",
pages="520-532",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0003-1224",
doi="",
url="http://dx.doi.org/"
}