Jamaludin, Jamaludin, Kosuke Mizuno, and Reda Rizal. “Economic Valuation of the Klapanunggal Karst Region Using the Travel Cost Method”. Jurnal Kepariwisataan Indonesia: Jurnal Penelitian dan Pengembangan Kepariwisataan Indonesia 18, no. 1 (June 30, 2024): 41–60. Accessed March 22, 2026. https://ejournal.kemenpar.go.id/index.php/jki/article/view/1003.