Sualang, Meyhard, Nelson Nainggolan, and John Kekenusa. “Optimasi Produksi Air Bersih Pelanggan PT. Air Manado Menggunakan Metode Goal Programming”. d’Cartesian 7, no. 1 (May 4, 2018): 29–34. Accessed May 11, 2024. https://ejournal.unsrat.ac.id/v3/index.php/decartesian/article/view/19551.