1. Some confounding factors in the study of mortality and occupational exposures;Gilbert;Am. J. Epidemiology,1982
2. A statistical method to control for the healthy worker effect in intracohort comparisons;Robins;Am. J. Epidemiology,1984
3. A new theory of causality in observational survival studies—Application to the healthy worker effect;Robins;Biometrics,1985
4. Bayesian inference for causal effects: The role of randomization;Rubin;Ann. Statist.,1978
5. Comment: Estimating the effects caused by treatment;Rosenbaum;J. Am. Statist. Assn.,1984