- Miller , D.C. 1926 . The Science of Musical Sounds , N.Y. : Macmillan .
- Lewis , Don . 1936 . “Vocal Resonance,” . Journal of the Acoustical Society of America , VIII : 91 – 99 .
- Laase , Leroy T. 1937 . “The Effect of Pitch and Intensity on the Quality of Vowels in Speech,” . Archives of Speech , II : 41 – 60 .
- Black , John W. 1937 . “The Quality of a Spoken Vowel,” . Archives of Speech , II : 7 – 27 .
Speech Monographs
Volume 5, 1938 - Issue 1