Harahap, Fitri Annisa, Saidun Hutasuhut, and Thamrin Thamrin. 2023. “Development of Flip Book-Based Economics Teaching Materials To Improve The Economic Learning Outcomes of Students In Class Xi Man 2 Deli Serdang In Academic Year 2021/2022”. Journal Research of Social Science, Economics, and Management 2 (6):938-56. https://doi.org/10.59141/jrssem.v2i06.356.