1. Double urethra;MacKenzie;Surg., Gynec. & Obst.,1916
2. Accessory urethra;Lowsley;New York J. Med.,1939
3. Duplication of the urethra;Gross;Arch. Surg.,1950
4. Sui canali anomali del pene;Taruffi;Bull. Sci. Med. Bologna,1891
5. Double and accessory urethra;Irmisch;Minnesota Med.,1946