Popham, W. J., & Sirotnik, K. A. (1973). Educational statistics: Use and interpretation (2d ed.). Harper & Row.
Cita Chicago (17th ed.)Popham, W. James, i Kenneth A. Sirotnik. Educational Statistics: Use and Interpretation. 2d ed. New York: Harper & Row, 1973.
Cita MLA (9th ed.)Popham, W. James, i Kenneth A. Sirotnik. Educational Statistics: Use and Interpretation. 2d ed. Harper & Row, 1973.
Atenció: Aquestes cites poden no estar 100% correctes.