Supriadi, Y., and B. D. Cahyani. “Formulation and Evaluation of Sappan Wood Extract Transparent Solid Soap With Variations in the Concentration of Glycerin As a Humectant”. Journal of Health Sciences and Medical Development, vol. 1, no. 02, Oct. 2022, pp. 58-67, doi:10.56741/hesmed.v1i02.156.