Inthaphan, J., O. Kaewboonchoo, P. Boonyamalik, and C. Chanyasanha. “Factors Related to Respiratory Symptoms Among Workers of A Highway District in Eastern Region”. Journal of Public Health Nursing, Vol. 35, no. 1, Apr. 2021, pp. 53-68, https://he01.tci-thaijo.org/index.php/phn/article/view/248692.