@article{ref1,
title="Reply to J. Kopp's critique of "levels of selection: an alternative to individualism in biology and the human sciences"",
journal="Social networks",
year="1991",
author="Wilson, David Sloan",
volume="13",
number="4",
pages="393-395",
abstract="<p>[Abstract unavailable]</p>",
language="en",
issn="0378-8733",
doi="10.1016/0378-8733(91)90004-D",
url="http://dx.doi.org/10.1016/0378-8733(91)90004-D"
}