Simanjorang, Lely Pratiwi, Irwan Sukri Banuwa, Rahmat Safe’i, and Agus Setiawan. “Economic Valuation of Sipiso-Piso Waterfall With Travel Cost Method and Willingness to Pay”. Jurnal Silva Tropika 2, no. 2 (December 30, 2018): 52-58. Accessed November 19, 2024. https://online-journal.unja.ac.id/STP/article/view/5423.