Saleem, Nadia, Aisha Din, Saba Sadiq, and Masroor Ahmed. “MDB As an Effective Platform of Communication Between Students and Teachers A Study of the Virtual University of Pakistan”. International Journal of Research in E-learning 4, no. 2 (February 1, 2021): 61-75. Accessed April 28, 2024. https://www.journals.us.edu.pl/index.php/IJREL/article/view/8353.