title: Importance of sampling frame in physician surveys.
authors.forename: G L
authors.initials: GL
authors.lastname: Freed
authors.forename: S J
authors.initials: SJ
authors.lastname: Clark
authors.forename: W C
authors.initials: WC
authors.lastname: Bordley
authors.forename: T R
authors.initials: TR
authors.lastname: Konrad
mesh_terms: D006293:Health Promotion; D006509:Hepatitis B / Q000517:prevention & control*; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D007229:Infant Welfare; D010372:Pediatrics / Q000706:statistics & numerical data*; D010818:Practice Patterns, Physicians'; D012494:Sampling Studies