KOURTIS, AP BOUSSIOTIS, VA LYMBERI, P PANGALIS, GA, INCREASED NATURAL ANTIBODY-ACTIVITY IN SERA OF PATIENTS WITH MALIGNANT NON-HODGKINS-LYMPHOMAS CONTAINING PARAPROTEINS, American Journal of Hematology, (46), 283-288, 1994, Wiley-Liss, Inc., 0361-8609, 1096-8652