Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers.
Michels KB, Joshipura KJ, Rosner BA, Stampfer MJ, Fuchs CS, Colditz GA, Speizer FE, Willett WC. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000 Nov 01; 92(21):1740-52.