1. Tonal experiments with whispered Thai;Abramson,1972
2. Random effects structure for confirmatory hypothesis testing: Keep it maximal;Barr;Journal of Memory and Language,2013
3. Bates, D., Maechler, M., Bolker, B., & Walker, S. (2015). lme4: Linear mixed-effects models using Eigen and S4. R package version 1.1-9., https://CRAN.R-project.org/package=lme4.
4. Intonational structure in Japanese and English;Beckman;Phonology,1986
5. Boersma, P., & Weenink, D. (2014). Praat: doing phonetics by computer [Computer program]. Version 5.3.57, retrieved 27 October, 2013. from http://www.praat.org/.