1. Baltes-Götz, B. (2013). Behandlung fehlender Werte in SPSS und Amos [Dealing with missing values in SPSS and Amos]. Universität Trier.
2. Belting, H., Dilly, H., Kemp, W., Sauerländer, W., & Warnke, M. (1996). Kunstgeschichte: Eine Einführung [Art history: An introduction]. In H. Belting, H. Dilly, W. Kemp, W. Sauerländer, & M. Warnke (Eds.) (6th ed.). Reimer.
3. Brown, J. D. (2009). Principal components analysis and exploratory factor analysis: Definitions, differences, and choices. Statistics, 13(1).
4. Campbell, D. T., & Fiske, D. W. (1959). Convergent and discriminant validation by the multitrait-multimethod matrix. Psychological Bulletin, 56(2), 81.
5. Cattaneo, M. (1994). Addressing culture and values in the training of art therapists. Art Therapy, 11(3), 184–186. https://doi.org/10.1080/07421656.1994.10759081