Ng, Li Mun, and Nur Anida Jumadi. “Non-Invasive Fetal Well-Being Monitoring Approaches: A Mini Review on Fetal Signal Separation Techniques”. International Journal of Integrated Engineering, vol. 16, no. 1, May 2024, pp. 251-6, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/16361.