@article{ref1,
title="Are the alternatives to randomized assignment nearly as good? Statistical corrections to nonrandomized evaluations",
journal="Journal of Policy Analysis and Management",
year="2009",
author="Pirog, Maureen A. and Buffardi, Anne L. and Chrisinger, Colleen K. and Singh, Pradeep and Briney, John",
volume="28",
number="1",
pages="169-172",
abstract="<p>[Abstract unavailable]</p>",
language="",
issn="0276-8739",
doi="10.1002/pam.20411",
url="http://dx.doi.org/10.1002/pam.20411"
}