1. Jao S-W, Beart RW Jr, Spencer RJ, Reiman HM, Ilstrup DM. Retrorectal tumors. Dis Colon Rectum 1985;28:644–52.
2. Dozois RR. Retrorectal cysts and tumors. 57th course: principles of colon and rectum surgery [abstract]. Minneapolis: University of Minnesota, 1994:78–83.
3. Gordon PH. Retrorectal tumors. In: Gordon PH, Navatvongs S, eds. Principles and practice of surgery for the colon, rectum, and anus. St. Louis: Quality Medical Publishing, 1992:383–400.
4. Kaiser TE, Pritchard DJ, Unni KK. Clinicopathologic study of sacrococcygeal chordoma. Cancer 1984;54:2574–8.
5. Gray SW, Singhabhandhu B, Smith RA, Skandalakis JE. Sacrococcygeal chordoma: report of a case and review of the literature. Surgery 1975;78:573–82.