Designing clinical research : an epidemiologic approach - Hulley, Stephen B.; Cummings, Steven R. 1947-; Browner, Warren S.; Grady, Deborah G.; Hearst, Norman (Philadelphia : Lippincott Williams & Wilkins, 2001)
Keywords: ENSAYOS CLINICOS -- TECNICAS; MEDICINA -- INVESTIGACIONES; MEDICINA; EPIDEMIOLOGIA