Kyfenko, Anna, and Tetyana Romanova. “A Method of Phase Formation of Vocal Sound at Activities of a Training Choral Collective”. ScienceRise: Pedagogical Education, no. 6 (39) (November 30, 2020): 4–7. Accessed November 23, 2024. https://journals.uran.ua/sr_edu/article/view/217050.