@Article{info:doi/10.2196/jmir.8.3.e20,
author="Christensen, Helen
and Mackinnon, Andrew",
title="The Law of Attrition Revisited",
journal="J Med Internet Res",
year="2006",
month="Sep",
day="29",
volume="8",
number="3",
pages="e20",
issn="1438-8871",
doi="10.2196/jmir.8.3.e20",
url="http://www.jmir.org/2006/3/e20/",
url="https://doi.org/10.2196/jmir.8.3.e20"
}