1. Welsh WH, Rose W. Institute of Hygiene: a report to the General Education Board of Rockefeller Foundation. New York: The Rockefeller Foundation; 1915. Available from URL: http://www.deltaomega.org /WelchRose.pdf (Accessed 5 January, 2011).
2. Fee E, Rosenkrantz B. Professional education for public health in the United States. In: Fee E, Acheson R, editors. History of Education in Public Health. New York: Oxford University Press;1991. pp. 230–271.
3. Terris M. Evolution of public health and preventive medicine in the United States. Am J Public Health. 1975;65:161–169.
4. Board on Health Promotion and Disease Prevention. The future of public health. Institute of Medicine of the National Academies. Washington, DC: National Academies Press; 1988. Available from URL: http://www.nap.edu /nap-cgi/report.cgi?record_id=1091&type=pdfxsum (Accessed 5 January, 2011).
5. Board on Health Promotion and Disease Prevention. The future of the public’s health in the 21st century. Institute of Medicine of the National Academies. Washington, DC: National Academies Press; 2002. Available from URL: http://books.nap.edu /openbook.php?record_id=10548 (Accessed 5 January, 2011).