1. 1) K. N. Stevens, Acoustic Phonetics (MIT Press, Cambridge, Mass., 1998).
2. Analog Studies Of The Nasalization Of Vowels
3. 3) G. Fant, Acoustic Theory of Speech Production (Mouton, The Hague, 1960).
4. 4) O. Fujimura, “Spectra of nasalized vowels,” Res. Lab. Electron. Q. Prog. Rep., No. 58, pp. 214–218 (1960).
5. 5) O. Fujimura, “Analysis of nasalized vowels,” Res. Lab. Electron. Q. Prog. Rep., No. 62, pp. 191–192 (1961).