Çam Aktaş, Bilge, and Yafes Can. “The Effect of ‘Whatsapp’ Usage on the Attitudes of Students Toward English Self-Efficacy and English Courses in Foreign Language Education Outside the School”. International Electronic Journal of Elementary Education, vol. 11, no. 3, Feb. 2019, pp. 247-56, https://www.iejee.com/index.php/IEJEE/article/view/722.