Calaminos, Franklin. “Development and Content Validation of Modular Textbook on Mathematics in the Modern World at Sorsogon State University, Sorsogon, Philippines”. EDUCATUM Journal of Science, Mathematics and Technology 11, no. 1 (January 16, 2024): 36–42. Accessed December 20, 2024. https://ojs.upsi.edu.my/index.php/EJSMT/article/view/8658.