Abdoerrachman, Hartono, Satoshi Imaizumi, Seiji Niimi, and Masanobu Kumada. 1996. “Objective Documented Study on Stipulated Target-Tone. Test of Vocal Controllability With the Electromyography Background Mechanism”. Medical Journal of Indonesia 5 (3), 158-64. https://doi.org/10.13181/mji.v5i3.865.