Priyono, Otto Andri. “Halal Tourism Opportunities And Challenges In East Java”. Ulumuna: Jurnal Studi Keislaman 4, no. 2 (December 10, 2018): 118–133. Accessed February 24, 2026. https://ejournal.kopertais4.or.id/madura/index.php/ulumuna/article/view/3479.