1. Oppenheim, V.A., and Schafer, W.R.: Digital Signal Processing, (Prentice-Hall, Englewood Cliffs, N.J. 1975)
2. Rabiner, R.L., and Gold, B.: Theory and Application of Digital Signal Processing, (Prentice-Hall, Englewood Cliffs, N.J. 1975)
3. Bogner, R.E., and Constantinides, A.C.: Introduction to Digital Filtering, (Wiley, New York 1975)