1. Epidemiology: Principles and Methods;MacMahon,1970
2. Foundations of Epidemiology;Lilienfeld,1976
3. Primer of Epidemiology;Friedman,1974
4. Epidemiology, an Introductory Text;Mausner,1974
5. Response and follow-up bias in cohort studies;Greenland;Am J Epid,1977