Wichaipon, Phannipa, Surin Makka, and Tawan Vikraipat. 2021. “The Study of Marketing Mix Affecting Purchasing Thai Herbal Soap Products in Wang Thonglang District, Bangkok Metropolis”. Rajapark Journal 15 (41). Bangkok, Thailand:273-82. https://so05.tci-thaijo.org/index.php/RJPJ/article/view/251205.