Muhamad Amir Irfan Roslan, et al. “Development of an Optical Handheld Device and Decision Tree for Mango Ripeness Classification Based on Sweetness Quality”. International Journal of Integrated Engineering, vol. 18, no. 1, Apr. 2026, pp. 215-28, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/24535.