Bumrungkij, A., M. Yamfang, and M. Janthong. “Development of a Mobile Measurement Device Prototype for Parallelity Measurement of Rails”. Science and Engineering Connect, vol. 44, no. 3, Sept. 2021, pp. 501-14, https://ph04.tci-thaijo.org/index.php/SEC/article/view/10446.