1. Fistulas of the posterior anal commissure;Brick;Tr. Am. Proct. Soc.,1909
2. Anal, perianal, perineal and sacrococcygeal sinuses;Nesselrod;Am. J. Surg.,1942
3. Anal and rectal fistula;Pennington;J. A. M. A.,1917
4. Diseases of the Rectum and Colon and Their Surgical Treatment;Lockhart-Mummery,1934
5. The posterior subsphincteric space;Courtney;Surg., Gynec. & Obst.,1949