N. Thanh Nhan and P. G. Anh Thu, “A Contribution to Teaching Vietnamese Music: Key Pitches in Context and the Pitch/intensity Contour Graph”, TCKHXHNV, vol. 3, no. 5, pp. 573–585, Oct. 2025, Accessed: Nov. 15, 2025. [Online]. Available: https://jossh.ussh.edu.vn/index.php/JOSSH-VN/article/view/357