Hutagaol J, Wicaksana EJ, Siburian J. Development of electronic handouts for class X high school ecosystem materials for online learning. J. Inov. Pend. IPA. [Internet]. 2022 Sep. 30 [cited 2025 May 22];8(2):121-30. Available from: https://journal.uny.ac.id/index.php/jipi/article/view/46536