1. Gabriel, W. B.: The Principles and Practice of Rectal Surgery. Ed. 3, Springfield, Ill., Charles C Thomas, 1945, p. 160.
2. Mentzer, C. G.: Anorectal disease. Pediat. Clin. North America, February, 1956, p. 113.
3. Rankin, F. W., J. A. Bargen and L. A. Buie: The Colon, Rectum and Anus. Philadelphia, W. B. Saunders Co., 1935, p. 593.
4. Schapiro, Saul: The occurrence of proctologic disorders in infancy and childhood: A statistical review of 2700 cases. Gastroenterology.15: 653, 1950.
5. Turrell, R., A. A. Pomeranz and S. M. Denmark: Collective review: Colon and anorectum in pediatric practice. Internat. Abstr. Surg.103: 209, 1956.