1. World Health Organization, Pneumonia, https://www.who.int/news-room/fact-sheets/detail/pneumonia (Accessed February 10, 2021).
2. UNICEF Indonesia, Kenali 6 Fakta tentang Pneumonia pada Anak, https://www.unicef.org/indonesia/id/stories/6-fakta-pneumonia(Accessed May 29, 2021).
3. Health Line, Why Pneumonia Can Be Deadly for Some People?, https://www.healthline.com/health/pneumonia/can-you-die-from-pneumonia Accessed July 2, 2021).
4. Sattar, S., & Sharma S, StatPearls Publishing (2021).
5. Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease: Table 1