1. The unit of analysis error in studies about physicians' patient care behavior;Divine;J. Gen. Intern. Med.,1992
2. CONSORT statement: extension to cluster randomised trials;Campbell;BMJ,2004
3. Advanced statistics:statistical methods for analyzing cluster and cluster-randomized data;Wears;Acad. Emerg. Med.,2002
4. Clustering in surgical trials - database of intracluster correlations;Cook;Trials,2012
5. Is there a surgeons' effect on patients' physical health, beyond the intervention, that requires further investigation? A systematic review;Schnelle;Therapeut. Clin. Risk Manag.,2022