1. Andersen, E. B. (1980). Discrete statistical models with social science applications. Amsterdam: North-Holland.
2. Bartels, R. (1985). Identification in econometrics. The American Statistician, 39, 102–104.
3. Bechger, T. M., & Maris, G. (2004). Structural equation modelling of multiple facet data. Extending models for multitrait–multimethod data. Psicológica, 25, 253–274.
4. Bechger, T. M., Verhelst, N. D., & Verstralen, H. F. M. (2001). Identifiability of nonlinear logistic test models. Psychometrika, 66, 357–371.
5. Bechger, T. M., Verstralen, H. F. M., & Verhelst, N. D. (2002). Equivalent linear logistic test models. Psychometrika, 67, 123–136.