Noviar, Iwan. “Development of a Portfolio Strategy in Learning to Write Expositional Essays in Grade XI Students of SMA Negeri 3 Samarinda”. Educationist: Journal of Educational and Cultural Studies 1, no. 1 (October 31, 2022): 142–154. Accessed October 7, 2025. https://jurnal.litnuspublisher.com/index.php/jecs/article/view/82.