Eskandari Shahraki, Majid, and Mehran Emadi. “Detection of Blood Vessels in Retina Images Using Gray Level Grouping Method”. Majlesi Journal of Telecommunication Devices 9, no. 1 (March 1, 2020): 1-8. Accessed April 7, 2020. http://journals.iaumajlesi.ac.ir/td/index/index.php/td/article/view/563.