1. Krane RJ, Goldstein I, Saenz de Tejada I: Impotence. N Engl J Med 321:1648–1659, 1989.
2. Steers WD: Neural control of penile erection. Sem Urol 8:66–79, 1990.
3. Lue TF: Physiology of erection and pathophysiology of impotence.In Campbell's Urology, ed. by P.C. Walsh, A.B. Retik, T.A. Stamey, E.D. Vaughan Jr, 6th ed., W.B. Saunders Company, pp 709–728, 1992.
4. Andersson K-E. Holmquist F: Mechanisms for contraction and relaxation of human penile smooth muscle. Int J Impotence Res 2:209–225, 1990.
5. Saenz de Tejada I: Mechanisms for the regulation of penile smooth muscle contractility.In World Book of Impotence, ed. by T.F. Lue, Smith-Gordon and Company Limited, London, pp 39–48, 1992.