1. Patent urachus and urachal cysts;Atala,1993
2. Urachal abnormalities;Gearhart,1998
3. The urachus;Begg;J Anat,1930
4. Congenital patent urachus and acquired variants;Blichert-Toft;Acta Clin Scand,1971
5. Urachal anomalies and related umbilical disorders;Bauer;Urol Clin North Am,1978