Pangsakunyanon, W., Y. Yupas, and S. Kenaphoom. “Performance Efficiency Development of Policeman in Provincial Police Region 4”. Journal for Developing the Social and Community, vol. 9, no. 3, Dec. 2022, pp. 573-90, https://so03.tci-thaijo.org/index.php/rdirmu/article/view/256429.