@article{ref1,
title="Sample selection bias, is misleading",
journal="Child abuse and neglect",
year="2001",
author="Sedlak, Andrea J. and Bruce, C. and Schultz, D. J.",
volume="25",
number="1",
pages="1-5",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="0145-2134",
doi="",
url="http://dx.doi.org/"
}