Nababan, Tongam Sihol, Raya Panjaitan, Ferry Panjaitan, and Kornel Munthe. “WILLINGNESS TO PAY: A PROXY TO PRODUCT PRICE”. Jurnal Manajemen dan Bisnis 21, no. 1 (April 17, 2021): 137–143. Accessed November 22, 2024. https://ejournal.ust.ac.id/index.php/JIMB_ekonomi/article/view/1192.