Wongpichet S, Watyotha C. The Suitability of The Utilization of Small Second-hand Agricultural Tractor : Case Study in Khon Kaen Province. Eng Appl Sci Res [internet]. 2013 Mar. 5 [cited 2026 Sep. 27];31(2):123-32. available from: https://ph01.tci-thaijo.org/index.php/easr/article/view/6707