1. Buie, L. A.: Practical Proctology. Ed. 2, Springfield, Illinois, Charles C Thomas, 1960, p. 163.
2. Buie, L. A. and W. L. Butsch: The importance of recognizing contracted anus. Am. J. Digest. Dis.5: 162, 1938–39.
3. Corréa Netto, A.: Tratamento cirúrgico do megacolo pela resecção dos chamados esfincteres funcionaes do intestino grosso (observação de 5 casos curados). Rev. cir. São Paulo.1: 249, 1934.
4. Courtney, Harold: Anatomy of the pelvic diaphragm and anorectal musculature as related to sphincter preservation in anorectal surgery. Tr. Am. Proct. Soc., 1949, p. 155.
5. Courtney, Harold: The posterior and subsphincteric space: Its relation to posterior horseshoe fistula. Surg., Gynec. & Obst.89: 222, 1949.