Phansi, P., and P. Klaythongpan. “Development of Marl Soap and Marl Mixed with Butterfly Pea Flower Extract Soap”. Research on Modern science and Utilizing Technological Innovation Journal (RMUTI Journal), vol. 17, no. 3, Oct. 2024, pp. 1-11, https://ph01.tci-thaijo.org/index.php/rmutijo/article/view/257352.