1. Barlow, D. H., & Hersen, M. (1984). Single case experimental designs (2nd ed.). New York: Pergamon Press.
2. Bertrand, J. T., Stover, J., & Porter, R. (1989). Methodologies for evaluating the impact of contraceptive social marketing programs. Evaluation Review, 13, 323–354.
3. Braverman, M. T., & Campbell, D. T. (1989). Facilitating the development of health promotion programs: Recommendations for researchers and funders. In M. T. Braverman (Ed.), Evaluating health promotion programs (pp. 5–18). New Directions for Program Evaluation, no. 43. San Francisco: Jossey-Bass.
4. Campbell, D. T., & Fiske, D. W. (1959). Convergent and discriminant validation by the multitrait-multimethod matrix. Psychological Bulletin, 56, 81–105.
5. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.) Hillsdale, NJ: Lawrence Erlbaum.