3Hambleton, R K : Advances in Assessment Models and Practices. In D C Berliner, R C Calfee (ed.). (1996). Handbook of Educational Psychology. New York:Simon & Schunster MaCmillan. p. 902.
4Oosterhof, A (2001). Classroom Applications of Educational Measurement. (3^rd.ed. )New Jersey:Merrill Prantion Hall.p.232.
5Borich, G D , Tombari, M L ( 1997 ). Educational psychology.(2^nd. ed. )New York: Longman, p. 429.
