Van De Donk NWCJ, Lokhorst HM, Dimopoulos M, Cavo M, Morgan G, Einsele H, Kropff M, Schey S, Avet-Loiseau H, Ludwig H, et al. Treatment of relapsed and refractory multiple myeloma in the era of novel agents. Cancer Treatment Reviews [Internet]. 2011;37(4):266 - 283.