Nigatu1,2 , W., N. D.J., C. . , B.J., B. D. W.G., and V. A.J. “Pre-and Post-Vaccine Measles Antibody Status in Infants Using Serum and Oral-Fluid Testing: An Evaluation of Routine Immunization in Addis Ababa, Ethiopia”. The Ethiopian Journal of Health Development, vol. 17, no. 3, Jan. 2017, https://ejhd.org/index.php/ejhd/article/view/722.