Warni, Silih. “Facilitating an Implementation of Online Portfolios in an EFL Writing Class”. Journal of ELT Research: The Academic Journal of Studies in English Language Teaching and Learning 2, no. 1 (February 1, 2017): 24–36. Accessed July 17, 2024. https://journal.uhamka.ac.id/index.php/jer/article/view/158.