The European Organization for Research and Treatment of Cancer QLQ‐C30: a quality-of-life instrument for use in international clinical trials in oncology. - Aaronson,N.K.; Ahmedzai,S.; Bergman,B.; Bullinger,M.; Cull,A.; Duez,N.J.; Filiberto,A.; Flechtner,H.; Fleishman,S.B.; Ddehaes,J.CJM.; Kaasa,S.; Klee,M.; et al. (J Natl Cancer Inst, 1993)