Acosta, Roy Albert N. “Development and Validation of Grade 10 Science Learning Materials in Selected Secondary Schools in District III, Division of Puerto Princesa City, Philippines”. Journal of Educational Research in Developing Areas 1, no. 3 (January 11, 2021): 248-264. Accessed April 18, 2024. https://jeredajournal.com/index.php/home/article/view/78.