1. Ramazzini B:Diseases of Workers. Translated from the Latin textDe Morbis Artificum of 1713 by Wilmer Cave Wright. Published under the auspices of the Library of the New York Academy of Medicine. New York: Hafner Publishing Co., 1964.
2. Hamilton A:Exploring the Dangerous Trades: The Autobiography of Alice Hamilton. Boston, MA: Northeastern University Press, 1985.
3. American Medical Association:Physician Characteristics and Distribution in the United States?1993. Chicago, IL: American Medical Association, 1993.
4. DeHart RL: Establishing Eligibility for Examination in the Specialty of Occupational Medicine.J of Occupational Medicine 28(4):303?305, 1986.
5. American Medical Association:Directory of Graduate Medical Education Programs. Chicago, American Medical Association, 1993.