Permana, Muhamad Diki, Lintang Kumoro Sakti, Annisa Luthfiah, M Lutfi Firdaus, Takahiro Takei, Diana Rakhmawaty Eddy, and Iman Rahayu. 2023. “A Simple Methods for Determination of Methylene Blue Using Smartphone-Based As Digital Image Colorimetry”. Trends in Sciences 20 (4). Nakhon Si Thammarat, Thailand:5149. https://doi.org/10.48048/tis.2023.5149.