Theamdee, Pawinee, Pakaporn Chawpaina, and Siraprapha Polthana. “The Preparation of PH Indicator Paper from Bagasse Fiber With Anthocyanin Extract from Butterfly Pea Flower, Purple Cabbage and Lxora Coccinea for an Acid-Base Soil Monitoring Application”. Research on Modern science and Utilizing Technological Innovation Journal (RMUTI Journal) 16, no. 1 (April 28, 2023): 15–27. Accessed May 20, 2024. https://ph01.tci-thaijo.org/index.php/rmutijo/article/view/250899.