ROSALINA, R.; GRAVITIANI, E. PENILAIAN WILLINGNESS TO PAY PERBAIKAN KUALITAS UDARA MENGGUNAKAN CONTINGENT VALUATION METHOD. Jurnal Ekonomi & Studi Pembangunan, [S. l.], v. 15, n. 2, p. 118–126, 2014. Disponível em: https://journal.umy.ac.id/index.php/esp/article/view/1225. Acesso em: 30 apr. 2025.