Indera, Edi, Marlon Sihombing, Chairul Muluk, and Rujiman . 2018. “Determination of Free Trade Zone and Free Port Development Area Development in Batam City, Riau Islands, Indonesia”. International Journal of Engineering & Technology 7 (3.30): 489-96. https://doi.org/10.14419/ijet.v7i3.30.18417.