1. Spitzer, W. O., and Brown, B.: Unanswered questions about the periodic health examination. Ann. Intern. Med. 83: 257–263, 1975.
2. Cypress, B. K.: The National Ambulatory Medical Care Survey: 1981 Summary. U S Department of Health and Human Services, National Center for Health Statistics, Hyattsville, MD, 1981.
3. Delbanco, T. L., and Noble, J.: The periodic health examination revisited. Ann. Intern. Med. 83: 271–273, 1975.
4. Delbanco, T. L., and Taylor, W. C.: The periodic health examination 1980. Ann. Intern. Med. 92: 251–252, 1980.
5. Spitzer, W. O.: Chairman: Report of the Task Force on the Periodic Health Examination. Can. Med. Assoc. J. 121: 1193–1254, 1979.