Wirachman, Rony, Sapriya Sapriya, and FauziGhani Muhammad. “Development of Ecological Intelligence of Elementary School Students Using Problem Based Instruction”. International Conference on Elementary Education 2, no. 1 (March 4, 2020): 1224-1233. Accessed October 8, 2024. http://proceedings2.upi.edu/index.php/icee/article/view/734.