Fitri, D.F., Armin, F. dan Djamaan, A. (2022) “Lapisan Polimer untuk Pupuk Slow-Release”, SIGn Journal of Science and Education, 1(1), hlm. 15–21. Tersedia pada: https://jurnal.penerbitsign.com/index.php/sjse/article/view/137 (Diakses: 26 September 2026).