@booklet {1591,
	title = {DIF analysis for pretest items in computer-adaptive testing (Educational Testing Service Research Rep No RR 94-33)},
	year = {1994},
	note = {$\#$ZW94-33},
	address = {Princeton NJ: Educational Testing Service.},
	author = {Zwick, R. and Thayer, D. T. and Wingersky, M.}
}
