Firmansyah, Risyad, Dwi Evi Zahraini, Veviola Indra F, Alfin Alfadilullah, and Revalina Austin Hartono. “Air Pollution Index As a Representation of Negative Externalities in Indonesia’s Major Cities”. Indonesian Journal Of Development And Economics 1, no. 2 (April 10, 2025): 78–95. Accessed August 8, 2026. https://journal.karyarisetnusantara.com/index.php/ijde/article/view/42.