Pattern of relapse in childhood ALL: challenges and lessons from a uniform treatment protocol. - Arya LS; Kotikanyadanam SP; Bhargava M; Saxena R; Sazawal S; Bakhshi S; Khattar A; Kulkarni KP; Adde M; Vats TS; Magrath I (Journal of pediatric hematology/oncology, 2010)