1. Berk, R. A. (1979). Generalizability of behavioral observations: a clarification of interobserver agreement and interobserver reliability. American Journal of Mental Deficiency, 83, 460–472.
2. Boring, E. G. (1953). A history of introspection. Psychological Bulletin, 50, 169–189.
3. Chomsky, N. (1965). Aspects of the theory of syntax. Cambridge: MIT Press.
4. Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 20, 37–46.
5. Cooper, J.O., Heron, T.E., & Heward, W.L. (2007). Applied behavior analysis (2nd ed.). Upper.