1. PAPAMICHALIS, P.E.: Practical approaches to speech coding, (Prentice Hall, Englewood Cliffs, NJ 1987)
2. QUACKENBUSH, S.R., BARNWELL, T.P., and CLEMENTS, M.A.: ‘Objective measures of speech quality’, (Prentice-Hall, Englewood Cliffs 1988)
3. STEENEKEN, H.J.M.: ‘Quality evaluation of speech processing systems’, INCE, A.N., Digital speech processing: speech coding, synthesis and recognition, (Kluwer Academic Publishers 1992)
4. `Introduction to dynastat,' downloaded from http://www.dynastat.com, March, 1999