Low serum bioactive luteinizing hormone in non-organic male impotence: possible relationship with altered gonadotropin-releasing hormone pulsatility. - Fabbri,A.; Iannini,E.A.; Ulisse,S.; Gnessi,L.; Moretti,C.; Frajese,G.; Isidori,A. (J Clin Endocrinol Metab, 1988)