SARI, Sinta widya; MASTHURA, Masthura; HUSNAH, Miftahul. The Effect of Variations in Cocoa Shell Carbon on the Characteristics of Environmentally Friendly Stamp Ink. Jurnal Phi : Jurnal Pendidikan Fisika dan Fisika Terapan, [S. l.], v. 11, n. 1, p. 45–51, 2025. DOI: 10.22373/p-jpft.v11i1.20137. Disponível em: https://jurnal.ar-raniry.ac.id/index.php/jurnalphi/article/view/20137. Acesso em: 8 aug. 2026.