References

1. Digital Signal Processing of Speech Signals,
L. R. Rabiner & R. W. Schafer, Prentice-Hall Inc, 1978.

2. Speech Communication, Human and Machine,
D. O'Shaugnessy, Addison-Wesley, 1987.

3. Signal and Systems,
A. V. Oppenhein & A. S. Wilsky, Prentice-Hall Inc, 1983.