Superiority of Oxaliplatin and Fluoruracil - Leucovorin compared with either therapy alone in patients with progressive colorectal cancer after Irinotecan and Fluoruracil - Leucovorin: Interim Results of a phase III trial. - Rothenberg,M.L.; Oza,A.M.; Bigelow,R.H. (J Clin Oncol, 2003)