More Groups
Fewer Groups
More People
Fewer People
Begg, C. B.; Zhang, Z. F.; Sun, M.; Herr, H. W.; Schantz, S. P. American Journal of Epidemiology (1995)
Meyers, P. A.; Heller, G.; Healey, J. H.; Huvos, A.; Applewhite, A.; Sun, M.; LaQuaglia, M. Journal of Clinical Oncology (1993)