Fijri Astuti, Tia, Chalina Chalina, and Mangatur Sinaga. “Development of E-Module for Writing Negotiation Texts Assisted by Flipbooks for Grade XI High School Students”. Jurnal Onoma: Pendidikan, Bahasa, dan Sastra 11, no. 2 (April 16, 2025): 1907–1917. Accessed July 24, 2025. https://e-journal.my.id/onoma/article/view/5076.