@book{205636,
	author = {Eldridge, Sandra. and Kerry, Sally M.},
	title = {A practical guide to cluster randomised trials in health services research /},
	publisher = {John Wiley & Sons,},
	year = {2012.},
	series = {Statistics in practice},
	address = {Chichester, West Sussex :},
	url = {http://onlinelibrary.wiley.com/book/10.1002/9781119966241}
}