J.S. Han, Speech Signal Processing. Seoul: Osung Media, 2000. ch . 2.
 A. Caruntu, G. Toderean, A. Nica, "Automatic Silence/Unvoiced/Voiced
Classification of Speech Using a Modified Teager Energy Feature,"
WSEAS, pp. 62-65, Nov., 2005
 WangRae Jo, JongKuk Kim, and Myung Jin Bae, "A Study on Pitch
Detection in Time-Frequency Hybrid Domain," Springer-Verlag, Lecture
Notes in Computer Science, vol. LNCS 3406, pp.437-440, Feb 2005.
 Hans Werner Strube , "Determination of the instant of glottal closure from
the speech wave," J., Acoust., Soc., Am, Vol. 5, No. 5, pp. 1625-1629,
 J.K. Kim, D.S. Na, M.J. Bae "On a pitch alteration technique in
transformation domain of speech signals," DCDIS, 2007. pp. 522-526
 M. Bae, J. Rheem, and S. Ann "A Study on Energy Using G-peak from the
Speech Production Model," KIEE, Korea, Vol. 24, No. 3, pp. 381-386,
 L. R. Rabiner and R. W. Schafer, Digital Processing of Speech signals.
New Jersey: Englewood Cliffs, Prentice-Hall, 1978, ch 6, 7.
 P. E. Paparnichalis, Practical Speech Processing. New Jersey:
Prentice-Hall, Inc, Englewood Cliffs, 1987.
 S. Seneff, "Real Time Harmonic Pitch Detection," IEEE Trans. Acoust.
Speech, and Signal Processing, Vol. ASSP-26, pp. 358-365, Aug. 1978.
 S. D. Stearns & R.A. David, Signal Processing Algorithms. New-Jersey:
Prentice-Hall, Inc, Englewood Cliffs, 1988.
 M.J. Bae, "On Detecting the Steady State Segments of Speech Waveform
by using the Normalized AMDF," IEEK, Vol.14, No.1, pp. 600-603, June,
 S. J. Kim. "A Segmentation Algorithm of the Connected Word Speech by
Statistical Method," IEEK, Vol.26, No. 4, pp. 151-162, Apr., 1989.
 M. J. Bae, and S. Ann, "Fundamental Frequency Estimation of Noise
Corrupted Speech Signals Using the Spectrum Comparison," J., Acoust.,
Soc., Korea, Vol. 8, No. 3, June 1989.