Siallagan, Frengky, Lois Oinike Tambunan, and Ropinus Sidabutar. 2023. “Pengembangan Instrumen Soal Higher Order Thinking Skill (HOTS) Pada Materi Bilangan Kelas VII SMP Negeri 2 Siantar”. Innovative: Journal Of Social Science Research 3 (6):8990-9004. http://j-innovative.org/index.php/Innovative/article/view/7512.