Cita APA (7a ed.)

Keighley, M. R., & Williams, N. S. (1999). Surgery of the anus, rectum and colon (2nd ed.). Saunders.

Cita Chicago Style (17a ed.)

Keighley, Michael R.B, y Norman S. Williams. Surgery of the Anus, Rectum and Colon. 2nd ed. London [etc.]: Saunders, 1999.

Cita MLA (9a ed.)

Keighley, Michael R.B, y Norman S. Williams. Surgery of the Anus, Rectum and Colon. 2nd ed. Saunders, 1999.