@article{ref1,
title="The design and use of cluster randomised controlled trials in evaluating injury prevention interventions: Part 2. Design effect, sample size calculations and methods for analysis",
journal="Injury prevention",
year="2010",
author="Coupland, Carol A. C. and DiGuiseppi, Carolyn G.",
volume="16",
number="2",
pages="132-136",
abstract="<p>[Abstract unavailable]</p> <p>Language: en</p>",
language="en",
issn="1353-8047",
doi="10.1136/ip.2009.023127",
url="http://dx.doi.org/10.1136/ip.2009.023127"
}