1. Fraumeni JFJr, Lloyd JW, Smith EM, Wagoner JK. Cancer mortality among nuns: Role of marital status in etiology of neoplastic disease in women. JNCI 1969; 42 455?68.
2. McMichael AJ, Potter JD. Reproduction, endogenous and exogenous sex hormones, and colon cancer risk: A review and a hypothesis. JNCI 1980; 65 1201?7.
3. Potter JD, McMichael AJ. Large bowel cancer in women in relation to reproductive and hormonal factors: A case-control study. JNCI 1983; 71 703?9.
4. Bjelke E. Epidemiologic studies of cancer of the stomach, colon, and rectum. Scand J Gastroenterol 1974; 9 31S: 1.
5. Peters RK, Pike MC, Chang WWL, Mack TM. Reproductive factors and colon cancer. Br J Cancer 1990; 61: 741?8.