TY  - RPRT
TI  - Sample size calculator for cluster randomized trials.
AU  - Marion K Campbell
AU  - Sean Thomson
AU  - Craig R Ramsay
AU  - Graeme S MacLennan
AU  - Jeremy M Grimshaw
PY  - 2004
DO  - 10.1016/s0010-4825(03)00039-8
UR  - https://pubmed.ncbi.nlm.nih.gov/14972631/
ID  - 14972631
ER  -