Sitinjak, W., Lubis, Z., Sibuea, M. B., Saragih, J. R., Aulia, M. R., & Sibuea, F. A. (2026). Market Integration and Price Transmission of Robusta Coffee in North Sumatra Province with the World Market. Agro Bali : Agricultural Journal, 9(2), 517–530. https://doi.org/10.37637/ab.v9i2.2849