Khan, M. I., A. Imran, A. H. Butt, and A. U. R. . Butt. “Activity Detection of Elderly People Using Smartphone Accelerometer and Machine Learning Methods”. International Journal of Innovations in Science & Technology, vol. 3, no. 4, Dec. 2021, pp. 186-97, https://journal.50sea.com/index.php/IJIST/article/view/96.