@inbook {1784,
	title = {Effectiveness of the ancillary estimation procedure},
	year = {1976},
	note = {{PDF file, 252 KB}},
	address = {C. K. Clark (Ed.), Proceedings of the First Conference on Computerized Adaptive Testing (pp. 103-106). Washington DC: U.S. Government Printing Office.},
	author = {Gugel, J. F. and Schmidt, F. L. and Urry, V. W.}
}
