1. Malformations of the umbilicus and urachus: Faulty closure of the vitello-intestinal duct and its results;Steinthal,1904
2. Embryology, Anatomy, and Diseases of the Umbilicus Together with Diseases of the Urachus;Cullen,1916
3. In search of the ideal female umbilicus;Craig;Plast Reconstr Surg,2000
4. The bladder and urethra;Gray,1972
5. Umbilical cord care: The effect of eight different cord-care regimens on cord separation time and other outcomes;Pezzati;Biol Neonate,2002