Fentaw, Surafel, et al. “Characterization of Invasive Pneumococcal Isolates Recovered from Patients in Two Selected Hospitals, Ethiopia”. Ethiopian Journal of Public Health and Nutrition (EJPHN), vol. 2, no. 1, Nov. 2017, pp. 65-70, https://ejphn.ephi.gov.et/index.php/ejphn/article/view/113.