Acquired von Willebrand disease in multiple myeloma secondary to absorption of von Willebrand factor by plasma cells - Richard, C; Cuadrado, M A; Prieto, M; Batlle, J; Fernandez, M FL; Salazar, M LR; Bello, C; Recio, M; Santoro, M T; Casares, M TG; Zubizarreta, A (Am J Hematol, 1990)