CEOP-21 versus CEOP-14 chemotherapy With or without rituximab for the first-line treatment of patients with aggressive lymphomas: Results of the HE22A99 trial of the hellenic cooperative oncology group (The Cancer Journal 2007 13 (327-334)) - Economopoulos, T.; Psyrri, A.; Dimopoulos, M.A. (Cancer Journal, 2007)