M. Lertvittayavivat, S. Chatpun, B. Petrović, M. Limaksorn, and P. Phukpattaranont, “Efficient EMG-Based Facial Expression Classification Using Minimal Time-Domain Features and the k-Nearest Neighbors Classifier”, Int. J. Onl. Eng., vol. 21, no. 13, pp. pp. 82–96, Nov. 2025.