@article{ref1,
title="The Business Cycle and Accidents to Railroad Employees in the United States",
journal="Journal of the American Statistical Association",
year="1931",
author="Campbell, CD",
volume="26",
number="175",
pages="295-302",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0162-1459",
doi="",
url="http://dx.doi.org/"
}