Hanafi, M., Irham, and L. R. Waluyati. “Factors Influencing Farmers’ Willingness to Pay for NPK Fertilizer in Specialty Coffee: Insights from Pagar Alam, Indonesia”. Research on World Agricultural Economy, vol. 5, no. 3, Sept. 2024, pp. 104-15, doi:10.36956/rwae.v5i3.1121.