More Groups
Fewer Groups
Brooks, D. D.; Winawer, S. J.; Rex, D. K.; Zauber, A. G.; Kahi, C. J.; Smith, R. A.; Levin, B.; Wender, R. American Family Physician (2008)
Oeffinger, K. C.; Sklar, C. A.; Hudson, M. M. American Family Physician (2003)