

@article {6705,
	title = {Calculating sample sizes for cluster randomized trials: {We} can keep it simple and efficient!},
	journal = {Journal of Clinical Epidemiology},
	volume = {65},
	number = {11},
	year = {2012},
	month = {nov},
	pages = {1212{\textendash}1218},
	issn = {08954356},
	doi = {10.1016/j.jclinepi.2012.06.002},
	url = {http://linkinghub.elsevier.com/retrieve/pii/S0895435612001692},
	author = {van Breukelen, Gerard J.P. and Candel, Math J.J.M.}
}
