Liu, lin-li, Yi Pang, and Zhuang-li Hu. “Application of Spectrogram Analysis in Traditional Vocal Music Teaching and Multimedia Animation Vocal Music Teaching”. International Journal of Emerging Technologies in Learning (iJET) 11, no. 11 (November 29, 2016): pp. 64–67. Accessed April 24, 2024. https://online-journals.org/index.php/i-jet/article/view/6242.