Mohanty, T., Patro, M., Sahoo, J., Meher, B. K., Pattnaik, M., & 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), 3698–3704. https://doi.org/10.18203/2320-6012.ijrms20184433