Phoophuangpairoj, Rong, and Niyomsri Srikun. 2014. “Computerized Recognition of Pineapple Grades Using Physicochemical Properties and Flicking Sounds”. International Journal of Agricultural and Biological Engineering 7 (3):93-101. https://www.ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/1063.