, R.R.KEOLE, H. S. Yawning detection and Head Nodding Detecion Analysis of Student Engagement during online Tutorials. International Journal of Engineering and Computer Science, india, v. 5, n. 11, 2018. Disponível em: http://ijecs.in/index.php/ijecs/article/view/3049. Acesso em: 18 may. 2024.