1. American Cancer Society,Cancer Facts and Figures(2001).
2. J. M. Crawford, “The gastrointestinal tract,” inPathologic Basis of Disease, R. S. Cotran, V. Kumar, and T. Collins, Eds., 6th Ed., Chap. 18, pp. 827–831, Saunders, Philadelphia, PA (1999).
3. Comparison of Colonoscopy and Double-Contrast Barium Enema