“Designing the Reverse Logistics of Newspaper Collection from Household by a Paper Recycling Unit: A Linear Programming Model” (2022) iJournals:International Journal of Software & Hardware Research in Engineering ISSN:2347-4890, 10(8). Tersedia pada: https://ijournals.in/journal/index.php/ijshre/article/view/170 (Diakses: 22 Oktober 2026).