KEIGHLEY, M. R. B., & WILLIAMS, N. S. (1999). Surgery of the anus, rectum and colon volume one.--ed.2. W.B. Saunders.

KEIGHLEY, Michael R. B., and Norman S. WILLIAMS. Surgery of the Anus, Rectum and Colon Volume One.--ed.2. London: W.B. Saunders, 1999.

KEIGHLEY, Michael R. B., and Norman S. WILLIAMS. Surgery of the Anus, Rectum and Colon Volume One.--ed.2. W.B. Saunders, 1999.