1. Accurate short-term analysis of the fundamental frequency and the harmonics-to-noise ratio in a sampled sound;Boersma;Proceedings of the Institute of Phonetic Sciences of the University of Amsterdam,1993
2. Boersma, P., & Weenink, D. (1996). Praat: A system for doing phonetics by computer. Technical Report 132, Institute of Phonetic Science of the University of Amsterdam.
3. A comparative acoustic study of English and Spanish vowels;Bradlow;Journal of the Acoustical Society of America,1995
4. Formant frequency values of vowels produced by preadolescent boys and girls;Busby;Journal of the Acoustical Society of America,1995
5. Men's voices and women's choices;Collins;Animal Behaviour,2000