V. Vijean, “Investigation of Valvular Heart Defects Through Phonocardiogram Signals”, IJIE, vol. 16, no. 1, pp. 328–336, Jun. 2024, Accessed: Apr. 09, 2026. [Online]. Available: https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/16349