Mohanty, T., Patro, M., Sahoo, J., Meher, B.K., Pattnaik, M. and Patra, J.K. 2018. Effectiveness of pneumococcal vaccine in patients with chronic obstructive pulmonary disease (COPD). International Journal of Research in Medical Sciences. 6, 11 (Oct. 2018), 3698–3704. DOI:https://doi.org/10.18203/2320-6012.ijrms20184433.