Schweizer, K., Moosbrugger, H., & Schermelleh-Engel, K. (2003). Models for Hierarchical Structures in Differential Psychology. In Methods of Psychological Research (Vols. 8, Issues 2, pp. 159-180). Department of Psychology - University of Koblenz-Landau. https://doi.org/10.23668/psycharchives.12788