De Cecco, J. P., & Crawford, W. R. (1988). The psychology of learning and instruction: Educational psychology (2d ed.). Prentice-Hall.

De Cecco, John P., and William R. Crawford. The Psychology of Learning and Instruction: Educational Psychology. 2d ed. Englewood Cliffs, N.J., New Delhi: Prentice-Hall, 1988.

De Cecco, John P., and William R. Crawford. The Psychology of Learning and Instruction: Educational Psychology. 2d ed. Prentice-Hall, 1988.