1. National trends in the prevalence and severity of the periodontal diseases;Douglass;JADA,1983
2. The potential for increase in the periodontal diseases of the aged population;Douglass;J Periodontol,1983
3. Basic data on dental examination findings of 1–74 years, United States, 1971–1974;Kelly,1979
4. Economies of scale and productivity in dental practices. Final report;Nash,1979
5. Decayed, missing and filled teeth among persons 1–74 years, United States, 1971–74;Harvey,1981