Rothman KJ, Arellano F. Elevating the level of scientific discourse. Int J Occup Environ Health. 2005 Sep 1;11(3):327-8.
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