Godding PR, McAnulty RD, Wittrock DA, Britt DM, Khansur T. Predictors of depression among male cancer patients. J Nerv Ment Dis. 1995 Feb 1;183(2):95-8.
Thissen D, Pommerich M, Billeaud K, Williams VSL. Item response theory for scores on tests including polychotomous items with ordered responses. Appl Psychol Meas. 1995;19(1):39-49.