Koepsell T.D., Martin D.C., Diehr P.H., et al. (1991). Data analysis and sample size issues in evaluations of community-based health promotion and disease prevention programs; a mixed-model analysis of variance approach. Journal of Clinical Epidemiology, 44: 701-713.
Feldman H.A., McKinlay S.M. (1994). Cohort versus cross-sectional design in large field trials: Precision, sample size, and a unifying model. Statistics in Medicine, 13: 61-78.
Atienza A.A., King A.C. (2002). Community-based health intervention trials: An overview of methodological issues. Epidemiologic Reviews, 24: 72-79.