Ahmat Alim, Mohamad Zain, and Nor'aisah Sudin. “Sleep Quality Monitoring and Notification System for Homecare Patient ”. Evolution in Electrical and Electronic Engineering, vol. 2, no. 2, Nov. 2021, pp. 925-34, https://publisher.uthm.edu.my/periodicals/index.php/eeee/article/view/4590.