Garcia-Albeniz X, Chan AT. Aspirin for the prevention of colorectal cancer. Best Pract Res Clin Gastroenterol. 2011 Aug;25(0):461-72. doi: 10.1016/j.bpg.2011.10.015
Johannes CB, Crawford SL. Menstrual bleeding, hormones, and the menopausal transition. Semin Reprod Endocrinol. 1999 Jan 1;17(4):299-309.
Williams VSL. The "unbiased" anchor: bridging the gap between DIF and item bias. Appl Meas Educ. 1997;10(3):253-67. doi: 10.1207/s15324818ame1003_4