Wittayarotwong, Sawanya, and Thoedsak Chomtohsuwan. 2021. “Financial Feasibility Study of Investment in Customs Tracking System through E-Lock Technology in Customs Free Zone”. Economics and Business Administration Journal Thaksin University 13 (2). Songkhla, Thailand:35-60. https://so01.tci-thaijo.org/index.php/ecbatsu/article/view/244285.