Gafur, A., O. K. Borggaard, J. Ravnsø Jensen, and L. Petersen. “Changes in Soil Nutrient Content under Shifting Cultivation in the Chittagong Hill Tracts of Bangladesh”. Geografisk Tidsskrift - Danish Journal of Geography, vol. 100, Jan. 2000, https://tidsskrift.dk/geografisktidsskrift/article/view/42384.