Incidence and clinical outcome of children with BCR/ABL-positive acute lymphoblastic leukemia (ALL). A prospective RT-PCR study based on 673 patients enrolled in the German pediatric multicenter therapy trials ALL-BFM-90 and CoALL-05-92 - Schlieben, Sigrid; Janssen, Johannes W. G.; Bartram, Claus R. (Leukemia, 1996)