1. Sur deaux cas de persistance de l’ouraque;Alric;Bull, de therap.,1879
2. Case of unclosed urachus with umbilical fistula;Annandale;Edinburgh Med. J.,1875
3. Surgical complications of congenital anomalies of the umbilical region;Arnheim;Surg. Gynec. & Obst.,1950
4. Urachal fistula;Ashhurst;Med. News,1882
5. Patent urachus with a report of two additional cases;Atcheson;J. Urol.,1944