Oppenheim, A. V., Schafer, R. W., Buck, J. R., Schafer, R. W., Schafer, R. W., & Buck, J. R. (1999). Discrete-time signal processing (2nd ed.). Upper Saddle River, N.J.: Prentice Hall.

Oppenheim, Alan V., Ronald W. Schafer, John R. Buck, Ronald W. Schafer, Ronald W. Schafer, and John R. Buck. Discrete-time Signal Processing. 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 1999.

Oppenheim, Alan V., et al. Discrete-time Signal Processing. 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 1999.