“Development of EKSIS (ebook Ekosistem) to Introduce the Ecosystem Concept in Class 3 Elementary School”. Primary: Jurnal Pendidikan Guru Sekolah Dasar 13, no. 5 (October 10, 2024): 224–233. Accessed May 9, 2025. https://primary.ejournal.unri.ac.id/index.php/JPFKIP/article/view/36.