Yuniar, Ainun Nisa, et al. “110. Improving Writing Skills of Personal Letter Through Problem Based Learning (PBL) Strategies Using Cue Card”. Prosiding Seminar Nasional Pendidikan Profesi Guru, vol. 1, no. 1, July 2023, pp. 1001-1, https://conference.upgris.ac.id/index.php/psnppg/article/view/4027.