Valentin, Marvin T., and Elmar M. Villota. 2015. “Design, Fabrication and Performance Evaluation of a Potato Grader for Village Level Operations Prototype II”. International Research Journal on Innovations in Engineering, Science and Technology 1 (2):42-49. https://ojs.batstate-u.edu.ph/index.php/IRJIEST/article/view/17.