Thavornwattanayong, W., K. Ratthanaphongtara, K. Phoyen, P. Suwankanit, and T. Kampanthong. “A Systematic Review of Economic Evaluation of Sequential of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine in Elderly People”. Science, Engineering and Health Studies, vol. 16, Jan. 2022, p. 22050001, doi:10.14456/sehs.2022.6.