Sri Rizki Sianturi, Advend, Amin Retnoningsih, and Saiful Ridlo. “Development of Interactive E-Book of Ferns Materials Through a Scientific Approach With HOTS Problems to Improve Student Learning Outcomes”. Journal of Innovative Science Education 10, no. 3 (December 6, 2021): 230-236. Accessed May 7, 2024. https://journal.unnes.ac.id/sju/jise/article/view/43091.