Heba, A., Smyrnova-Trybulska, E., & Kapounová, J. (2017). Objectives and Content of the Mathematics E-learning Course Preparing Students for the School-leaving Exam in Mathematics. International Journal of Research in E-Learning, 3(1), 109–124. Retrieved from https://trrest.vot.pl/ojsus/index.php/IJREL/article/view/8398