1. Elements of General Phonetics;Abercombie,1967
2. NLTK: the natural language toolkit;Bird,2006
3. A formal framework for linguistic annotation;Bird;Speech Commun.,2001
4. Boersma, P., Weenink, D., 2016. Praat: doing phonetics by computer (Version 6.0.19). http://www.fon.hum.uva.nl/praat/.
5. Recent developments in the Emu speech database system;Bombien,2006