1. Bacon HE, Recio PM: Surgical Anatomy of the Colon, Rectum and Anal Canal. Philadelphia, Lippincott, 1962, p 70
2. Hanley PH: Retrorectal tumors.In Turell R: Diseases of the Colon and Anorectum. Ed. 2, Philadelphia, Saunders, 1969, vol 2, p 1143
3. Hughes ES, Cuthbertson AM: Anorectal Surgery. Sydney, Hicks, 1974, p 17
4. Levy E: Pathognomonic triad and retrorectal abscess: The surgical approach. Dis Colon Rectum 8:61, 1965
5. Ranson JH, Harris MN: Retrorectal epidermoid cyst: Report of a case. Dis Colon Rectum 12: 26, 1969