Rahman, Arif, Niken Tunjung Murti Pratiwi, and Sigid Hariyadi. 2017. “Struktur Komunitas Fitoplankton Di Danau Toba, Sumatera Utara”. Jurnal Ilmu Pertanian Indonesia 21 (2), 120-27. https://doi.org/10.18343/jipi.21.2.120.