Hardiyanti, T., D. Paningrum, and A. B. Sutopo. “Marketing Mix 9P Strategy in Sustaining a Souvenir Shop Business: Strategi Marketing Mix 9P Dalam Mempertahankan Bisnis Toko Souvenir”. Indonesian Journal of Innovation Studies, vol. 26, no. 3, July 2025, p. 10.21070/ijins.v26i3.1579, https://ijins.umsida.ac.id/index.php/ijins/article/view/1579.