1. Andi-Pallawa, B., & Fiptar Abdi Alam, A. (2013). A comparative analysis between English and Indonesian phonological systems. International Journal of English Language Education, 1(3). https://doi.org/10.5296/ijele.v1i3.3892.
2. Ball, M. J., & Muller, N. (2005). Articulation: Consonant manner types. Phonetics for communication disorders (pp. 63–73). New York: Psychology Press.
3. Bao, H., & Zheng, Y. (2011). Putonghua Dongtai Ewei Yanjiu. [An electropalatography study on the articulation of Standard Chinese]. Journal of School of Chinese Language and Culture Nanjing Normal University, 03, 1–11. (in Chinese).
4. Best, C. T. (1995). A direct realist view of cross-language speech perception. In W. Strange (Ed.), Speech perception and linguistic experience: Issues in cross-language research (pp. 171–204). Baltimore, MD: York Press.
5. Best, C. T., & Tyler, M. D. (2007). Nonnative and second-language speech perception: Commonalities and complementarities. In M. J. Munro & O.-S. Bohn (Eds.), Language experience in second language speech learning (pp. 13–34). Amsterdam: John Benjamins Publishing.