Importance of sampling frame in physician surveys.
Freed
G L
GL
Clark
S J
SJ
Bordley
W C
WC
Konrad
T R
TR
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