Prasert, K. ., J. Patumanond, J. Rattanayot, J. Thungthong, M. Shrestha, S. Chawalchitiporn, S. Nakphook, S. Sirikhetkon, and S. Iamsirithaworn. “Seasonal influenza vaccine effectiveness among persons with COPD in Thailand: a retrospective national cohort study”. Journal of Public Health and Development, vol. 19, no. 2, May 2021, pp. 180-0, https://he01.tci-thaijo.org/index.php/AIHD-MU/article/view/245420.