1. Congenital patent urachus and acquired variants;Blichert-Toft;Acta Chir Scand,1971
2. Patent urachus;Herbst;S Med J,1937
3. The urachus and umbilical fistulae;Beg;Surg Gynecol Obstet,1927
4. Surgical disorders of the bladder and umbilicus of urachal origin;Hinman;Surg Gynecol Obstet,1961
5. Surgical abnormalities in urachus remnants in adults;De Geus;Arch Chir Neerlandieum,1968