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PhillipsBETTY JANE WILSON. “Evaluation of Two Methods of Teaching Selected Consonant Sounds to Primary Grade Children,” D.Ed. dissertation. The Penna. State University, 1951.
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TemplinMILDRED. “Norms on a Screening Test of Articulation for Ages Three through Eight,” Journal of Speech and Hearing Disorders, 18, 1953, p. 323–31.
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Van RiperCHARLES. Speech Correction—Principles and Methods, 1954. Rev. Ed., Prentice-Hall, New York, p. 125.