More Groups
Fewer Groups
More People
Fewer People
Breitbart, W.; Passik, S.; McDonald, M. V.; Rosenfeld, B.; Smith, M.; Kaim, M.; Funesti-Esch, J. Pain (1998)
Smith, M. Y.; DuHamel, K.; Johnson Vickberg, S.; Papadopoulos, E.; Redd, W. H.; Ricketts, P. Psychosomatic Medicine (1997)