Chaowarat, P., M. Piriyakannon, S. Sawangchan, and W. Natrephra. “Soft Measures for Cycling Promotion in the Northeast of Thailand”. Chophayom Journal, vol. 29, no. 3, Dec. 2018, pp. 69-84, https://so01.tci-thaijo.org/index.php/ejChophayom/article/view/163909.