Não informado. University of Pennsylvania medical bulletin. University of Pennsylvania, School of Medicine.
Chicago-referens (17:e uppl.)Não informado. University of Pennsylvania Medical Bulletin. Philadelphia, Pa: University of Pennsylvania, School of Medicine.
MLA-referens (8:e uppl.)Não informado. University of Pennsylvania Medical Bulletin. University of Pennsylvania, School of Medicine.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.