P. Lorigan, J. Verweij, Z. Papai, et al. Phase III trial of two investigational schedules of ifosfamide compared with standard- dose doxorubicin in advanced or metastatic soft tissue sarcoma: A European organisation for research and treatment of cancer soft tissue and bone sarcoma group study. Journal of Clinical Oncology, 2007, 25(21): 3144-3150.