1. DuBois WEB. The Philadelphia Negro: A Social Study, 1899. Available at: http://www.webdubois.org/wdb-phila.html (Full text of the 1967 Schocken edition (with E. Digby Baltzell’s Introduction) available in PDF formats at http://www.archive.org/details/philadelphianegr001901mbp). Accessed October 7, 2010).
2. The Philadelphia Negro: A Social Study;DuBois,1996
3. Scientific diagnosis and treatment of the community as a patient;McGavran;JAMA,1956
4. NIH Definition of Research. Available at: Accessed at the NIH Office of Extramural Research website on February 27, 2011.
5. NIH Definition of Clinical Research. NIH Office of Extramural Research website. Available at: http://grants.nih.gov/grants/glossary.htm#C. Accessed February 27, 2011.