Edi Sumarno, Ginting, J. S., Karina, N. and Lubis, M. A. R. (2019) “The Factors in the Emergence of Smallholder Rubber Plantation in Tapanuli: 1906 - 1942”, International Journal of Culture and Art Studies, 3(1), pp. 22-29. doi: 10.32734/ijcas.v3i1.2623.