TY  - RPRT
TI  - Sample size in cluster randomisation.
AU  - S M Kerry
AU  - J M Bland
PY  - 1998
DO  - 10.1136/bmj.316.7130.549
UR  - https://pubmed.ncbi.nlm.nih.gov/9501723/
ID  - 9501723
ER  -