References
- Muriel Morley — The Development and Disorders of Speech in Childhood, E. & S. Livingstone Limited, Edinburgh and London, Page 2: 1957.
- Fröschels and Jellinek — The Practice of Voice and Speech Therapy, Pub.: Expression Company, Boston, Mass., Page 254: 1941.
- Arnold Gesell — The First Five Years of Life, Harper & Brothers, New York and London, Page 25: 1955.
- Ibid, Page 19-20. .
- Ibid, Page 21
- Ernest Gardner — Fundamentals of Neurology, Fourth Edition, W. B. Saunders Company, Philadelphia and London, Page 302: 1963.
- Ibid, Page 302.
- A. G. Mitchell — Spoken English, Page 88-89: 1962. (Ibid) diagrams (a) (b) (c) after A. G. Mitchell, Spoken English, 1962, Pages 99, 100, 101 consecutively, Macmillan and Co. Limited, New York, St. Martin’s Press.
- Diagram (d), After Ida Ward, The Phonetics of English, Cambridge — W. Heffer and Sons Limited, Page 148: 1958.