title: Observational studies in clinical research.
authors: Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis, MN 55454, USA. luepker@epi.umn.edu
authors: Russell V
authors: RV
authors: Luepker
mesh_terms: D035843:Biomedical Research / Q000379:methods*; D016022:Case-Control Studies; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006801:Humans; D019370:Observation