Usi, Usiminda, et al. “Pengembangan E-Modul Berbasis Problem Based Learning Untuk Memfasilitasi Higher Order Thinking Skills (HOTS) Siswa”. Indo-MathEdu Intellectuals Journal, vol. 6, no. 1, Feb. 2025, pp. 1110-2, doi:10.54373/imeij.v6i1.2540.