Fakhurozi, Ahmad, et al. “Analysis of Environmental Impact and Municipal Waste Management Strategy: A Case of the Piyungan Landfill, Yogyakarta, Indonesia”. Jurnal Optimasi Sistem Industri, vol. 20, no. 1, May 2021, pp. 61–71, http://josi.ft.unand.ac.id/index.php/josi/article/view/156.