1. The incidence of umbilical hernia in Africans;Mack;East Afr Med J,1945
2. Umbilical hernia;Crump;J Pediatr,1952
3. The natural history of umbilical hernia;Walker;Clin Pediatr,1967
4. Disorders of the umbilicus;Light,1978
5. Umbilical hernia;Santulli,1977