Bacci, G., S. Ferrari, A. Longhi, D. Donati, M. De Paolis, C. Forni, M. Versari, E. Setola, A. Briccoli and E. Barbieri (2003). "Therapy and survival after recurrence of Ewing's tumors: the Rizzoli experience in 195 patients treated with adjuvant and neoadjuvant chemotherapy from 1979 to 1997." Ann Oncol 14(11): 1654-1659. 4.