Anwar, U., Y. Patadungan, and I. Isrun. “Perubahan Sifat Kimia Tanah Serta Pertumbuhan Sawi (Brassica Juncea) Akibat Pemberian Limbah Cair Pabrik Kelapa Sawit”. AGROTEKBIS : JURNAL ILMU PERTANIAN (e-Journal), Vol. 7, no. 2, Apr. 2019, pp. 179 -85, http://jurnal.faperta.untad.ac.id/index.php/agrotekbis/article/view/400.