A randomised clinical trial comparing interferon-alpha and intravenous immunoglobulin in polyneuropathy associated with monoclonal IgM. The IgM-associated Polyneuropathy Study Group - Mariette,X.; Chastang,C.; Clavelou,P.; Louboutin,J.P.; Leger,J.M.; Brouet,J.C. (J Neurol Neurosurg Psychiatry, 1997)