Waruwu, Pikiran. “Improving Learning Outcomes of Writing Negotiation Texts Through the Application of Cooperative Learning Model”. Jurnal Ilmu Multidisiplin Indonesia 1, no. 2 (September 30, 2024): 53–58. Accessed July 12, 2025. https://jurnal.stkipahsingaraja.ac.id/index.php/jimi/article/view/901.