TY  - RPRT
TI  - Balance in cluster randomized trials.
AU  - G M Raab
AU  - I Butcher
PY  - 2001
DO  - 10.1002/1097-0258(20010215)20:3<351::aid-sim797>3.0.co;2-c
UR  - https://pubmed.ncbi.nlm.nih.gov/11180306/
ID  - 11180306
ER  -