P. M. R. Bubun, K. L. Theffie, and R. I. Kawulusan, “Identification Of Potassium, Organic Carbon and Soil Ph on Sloping Land of Cabbage Crops at Agrotourism Area Rurukan Sub-District”, SaEJ, vol. 2, no. 1, pp. 20–25, Nov. 2024.