Bogerd HP, Wiegand HL, Yang J, Cullen BR. Mutational definition of functional domains within the Rev homolog encoded by human endogenous retrovirus K. J Virol. 2000 Oct;74(20):9353-61.
Scrams DJ, McLeod LD. An expected response function approach to graphical differential item functioning. J Educ Meas. 2000 Jan 1;37(3):263-77.