van de Donk NW, Palumbo A, Johnsen HE, Engelhardt M, Gay F, Gregersen H, Hajek R, Kleber M, Ludwig H, Morgan G, Musto P, Plesner T, Sezer O, Terpos E, Waage A, Zweegman S, Einsele H, Sonneveld P, Lokhorst HM. The clinical relevance and management of monoclonal gammopathy of undetermined significance and related disorders: recommendations from the European Myeloma Network. Haematologica 2014; 99(6):984-996; https://doi.org/10.3324/haematol.2013.100552.