Saputri, Aprilia Eki. “The DEVELOPMENT PRINCIPLE OF A CONTEXTUAL BASED TEACHING BOOK ON ENVIRONMENTAL EDUCATION FOR PRIMARY SCHOOL TEACHERS”. Jurnal Ilmiah Pendidikan Lingkungan dan Pembangunan 22, no. 01 (August 2, 2021): 43 - 49. Accessed May 8, 2025. http://103.8.12.212:33180/unj/index.php/plpb/article/view/16966.