1. Parkkulainen, K. V.: Posterior urethral obstruction: valvular or diaphragmatic? Endoscopic diagnosis and treatment. In: Birth Defects: Urinary System Malformations in Children. Edited by D. Bergsma and J. W. Duckett. New York: Alan J. Liss, Inc., pp. 63–74, 1977
2. Wigglesworth, J. S.: The kidneys and urinary tract: urinary bladder and urethra. In: Major Problems in Pathology. Philadelphia: W. B. Saunders Co., vol. 15, pp. 364–370, 1984
3. Congenital diaphragmatic obstruction of the male urethra;Robertson;Br J Urol,1969
4. Jarjavay, J. F.: Recherches anatomiques sur l’uréthre de l’homme. Paris, 1856
5. Congenital stricture of the proximal urethral bulb;Cobb;J Urol,1968