W. . Phetliap and V. . Khetbumrung, “Factors Related to the Use of Personal Protective Equipment among the farmers aged over 50 years in Pudsa Sub-district, Mueang District, Nakhon Ratchasima Province”, Journal of the office of disease prevention and control 9 Nakhon Ratchasima, vol. 28, no. 1, pp. 16–26, Jan. 2022.