Sitorus, Y.R. and Mardina, V. 2020. Karakteristik Kimia dari Penggolahan Limbah Cair PTPN Y, Sumatera Utara. Jurnal EnviScience (Environment Science). 4, 2 (Sep. 2020), 58–66. DOI:https://doi.org/10.30736/4ijev.v4iss2.197.