1. Hulley S, Grady D, Bush T, et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women: Heart and Estrogen/progestin Replacement Study (HERS) Research Group. JAMA 1998;280:605-13.
2. Rossouw JE, Anderson GL, Prentice RL, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women’s Health Initiative randomized controlled trial. JAMA 2002;288:321-33.
3. Hersh AL, Stefanick ML, Stafford RS. National use of postmenopausal hormone therapy: annual trends and response to recent evidence. JAMA 2004;291:47-53.
4. Coope J, Thomson JM, Poller L. Effects of “natural oestrogen” replacement therapy on menopausal symptoms and blood clotting. BMJ 1975;4:139-43.
5. Cauley JA, Robbins J, Chen Z, et al. Effects of estrogen plus progestin on risk of fracture and bone mineral density: the Women’s Health Initiative randomized trial. JAMA 2003;290:1729-38.
6. Cook LS, Weiss NS. Endometrial cancer. In: Goldman MB, Hatch MC, editors. Women & health. London: Academic Press; 2000:916-31.
7. Beresford SA, Weiss NS, Voigt LF, McKnight B. Risk of endometrial cancer in relation to use of oestrogen combined with cyclic progestagen therapy in postmenopausal women. Lancet 1997;349:458-61.
8. Weiderpass E, Adami HO, Baron JA, et al. Risk of endometrial cancer following estrogen replacement with and without progestins. J Natl Cancer Inst 1999;91:1131-7.
9. Beral V, Bull D, Reeves G, Million Women Study collaborators. Endometrial cancer and hormone-replacement therapy in the Million Women Study. Lancet 2005;365:1543-51.
10. Pike MC, Peters RK, Cozen W, et al. Estrogen- progestin replacement therapy and endometrial cancer. J Natl Cancer Inst 1997;89:1110-6.
11. Strom BL, Schinnar R, Weber AL, et al. Case-control study of postmenopausal hormone replacement therapy and endometrial cancer. Am J Epidemiol 2006;164:775-86.
12. Newcomb PA, Trentham-Dietz A. Patterns of postmenopausal progestin use with estrogen in relation to endometrial cancer (United States). Cancer Causes Control 2003;14:195-201.
13. Jain MG, Rohan TE, Howe GR. Hormone replacement therapy and endometrial cancer in Ontario, Canada. J Clin Epidemiol 2000;53:385-91.
14. Lacey JV, Brinton LA, Lubin JH, Sherman ME. Endometrial carcinoma risks among menopausal estrogen plus progestin and unopposed estrogen users in a cohort of postmenopausal women. Cancer Epidemiol Biomarkers Prev 2005;14:1724-31.
15. Hill DA, Weiss NS, Beresford SA, et al. Continuous combined hormone replacement therapy and risk of endometrial cancer.AmJ Obstet Gynecol 2000;183:1456-61.
16. Marchbanks PA, McDonald JA, Wilson HG, et al. The NICHD women’s contraceptive and reproductive experiences study: methods and operational results. Ann Epidemiol 2002;12:213-21.
17. Hankey BF, Ries LA, Edwards BK. The surveillance, epidemiology, and end results program: a national resource. Cancer Epidemiol Biomarkers Prev 1999;8:1117-21.
18. Waksberg J. Sampling methods for random digit dialing. J Am Stat Assoc 1978;73:40-6.
19. Voigt LF, Weiss NS, Chu J, Daling JR, Mc- Knight B, van Belle G. Progestagen supplementation of exogenous oestrogens and risk of endometrial cancer. Lancet 1991;338:274-7.
20. Jain MG, Rohan TE, Howe GR. Agreement of self-reported use of menopausal hormone replacement therapy with physician reports. Epidemiology 1999;10:260-3.
21. Strom BL, Schinnar R. An interview strategy was critical for obtaining valid information on the use of hormone replacement therapy. J Clin Epidemiol 2004;57:1210-3.
22. Effects of hormone replacement therapy on endometrial histology in postmenopausal women: the Postmenopausal Estrogen/Progestin Interventions (PEPI) trial: the Writing Group for the PEPI trial. JAMA 1996;275:370-5.
23. Anderson GL, Judd HL, Kaunitz AM, et al. Effects of estrogen plus progestin on gynaecologic cancers and associated   diagnostic procedures: the Women’s Health Initiative randomized trial. JAMA 2003;290:1739-48.
24. Koepsell TD, Weiss NS. Epidemiologic methods: studying the occurrence of illness.NewYork: Oxford University Press; 2003: 328.
25. Reed SD, Voigt LF, Beresford SA, Hill DA, Doherty JA, Weiss NS. Dose of progestin in postmenopausal-combined hormone therapy and risk of endometrial cancer. Am J Obstet Gynecol 2004;191:1146-51.
26. Persson I, Weiderpass E, Bergkvist L, Bergstrom R, Schairer C. Risks of breast and endometrial cancer after estrogen and estrogen-progestin replacement. Cancer Causes Control 1999;10:253-60.
27. Jick SS, Walker AM, Jick H. Estrogens, progesterone, and endometrial cancer. Epidemiology 1993;4:20-4.
28. Brinton LA, Hoover RN. Estrogen replacement therapy and endometrial cancer risk: unresolved issues: the Endometrial Cancer Collaborative group. Obstet Gynecol 1993; 81:265-71.