Wahyuni, Yuli, and Muhammad Abdulrohman Pany. “Heart Rate Detection of Stress Levels for Pregnant Women”. Indonesian Journal of Applied Research (IJAR) 3, no. 1 (May 12, 2022): 46-55. Accessed April 24, 2024. https://iojs.unida.ac.id/index.php/IJAR/article/view/182.