Aprinawati, and Rangga Restu Prayogo. “Halal Tourism: Implication for Tourism Industry in Danau Toba, Indonesia”. Ulum Islamiyyah 34, no. 1 (December 16, 2022): 1–14. Accessed July 3, 2024. https://uijournal.usim.edu.my/index.php/uij/article/view/339.