“KUALITAS DAMAR POHON POOTI (HOPEA GREGARIA) BERDASARKAN UJI VISUAL, BILANGAN ASAM, DAN KADAR ABU: Quality of Pooti Dammar Resin (Hopea gregaria) Based on Visual Test, Acid Number, and Ash Content”, perennial, vol. 17, no. 1, hlm. 1–4, Apr 2021, doi: 10.24259/perennial.v17i1.12646.