Suphanchaimat, R., A. Bamrung, and P. Kowit. “Relationship Between Concentration of Traffic Accident Incidence by Various Causes and Provincial Eco-Nomic Status: An Application of Concentration Index”. Journal of Health Science of Thailand, vol. 26, no. 5, Oct. 2017, pp. 821-8, https://thaidj.org/index.php/JHS/article/view/1.