GuilfordJ.Psychometric methods. (2nd ed.) New York: McGraw-Hill, 1954.
2.
SilvermanF.Correspondence between mean and median scale values for sets of stimuli scaled by the method of equal-appearing intervals. Percept. mot. Skills, 1967, 25, 727–728.
3.
WinerB.Statistical principles in experimental design.New York: McGraw-Hill, 1962.
