Zainal Abidin, Z., N. Zakaria, Z. Ayop, and N. Harum. “Development of Pupil Detection in Eye Movement With Raspberry Pi”. International Journal of Human and Technology Interaction (IJHaTI), vol. 2, no. 2 October, Oct. 2018, pp. 43-48, https://ijhati.utem.edu.my/ijhati/article/view/4446.