1. Structural Equations with Latent Variables
2. BV, T. S. (2019, April 13). Tiobe index. Retrieved from https://www.tiobe.com/tiobe-index/
3. Carbonnelle, P. (2019, April 13). Pypl popularity of programming language. Retrieved from http://pypl.github.io/PYPL.html
4. Dai, C. (2018). pypsy: Psychometrics package. Retrieved from https://pypi.org/project/psy/
5. Polychoric and Polyserial Correlations