1. ALBERY, E. 1991, Consonant Articulation in Different Types of Cleft Lip and Palate, Unpublished MPhil Thesis, Leicester Polytechnic, UK
2. BERNTHAL, J.E., and BANKSON, N.W., 1988, Articulation and Phonological Disorders (Englewood Cliffs, NJ: Prentice Hall)
3. FLETCHER, S.G., 1978, Diagnosing Speech Disorders from Cleft Palate (New York: Grune & Stratton)
4. GRUNWELL, P. 1993, Analysing Cleft Palate Speech (London: Whurr Publishers)
5. McWiniAms, B.J. MORRIS, H.L., and SHELTON, R.L., 1990, Cleft Palate Speech, second edition (Philadelphia, PA: B.C. Decker)