Suharyadi, H., T. J. Soewardi, S. M. Frampton, F. Afifah, and C. Christopher. “Resource Valuation of Kalilingseng-Cave Manganese Mining Site As a Tourist Destination Using the Travel Cost Method”. Indonesian Journal of Innovation Studies, Vol. 25, no. 4, Sept. 2024, p. 10.21070/ijins.v25i4.1300, doi:10.21070/ijins.v25i4.1300.