Rengganis, Amalia Puspita, Sulhadi Sulhadi, Teguh Darsono, and Dhamar Putra Fajar. 2017. “FABRIKASI TINTA SPIDOL WHITEBOARD BERBAHAN DASAR PIGMEN ORGANIK DARI ENDAPAN MINUMAN KOPI”. PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) 6 (October):SNF2017-MPS. https://doi.org/10.21009/03.SNF2017.02.MPS.17.