halimah, Sofiati, et al. “Optimization of Teak Leaf Extract (Tectona Grandis L.F) and Carbopol in Hair Dye Formulation Using Factorial Design Method”. JURNAL KESEHATAN, SAINS, DAN TEKNOLOGI (JAKASAKTI), vol. 4, no. 2, Aug. 2025, pp. 342-55, https://jurnal.undhirabali.ac.id/index.php/jakasakti/article/view/4283.