1. Webb, E.J., Campbell, D.T., Schwartz, R.D., and Sechrest, L. (1966). Unobtrusive Measures, Rand McNally.
2. Computational thinking;Wing;Commun. ACM,2006
3. Freudenthal, H. (1978). Weeding and Sowing, Kluwer.
4. Abramovich, S. (2023). Computational triangulation in mathematics teacher education. Computation, 11.
5. Denzin, N.K. (1970). The Research Act in Sociology: The Theoretical Introduction to Sociological Methods, Butterworth.