Donbraye, E., Adewumi, M., Odaibo, G., Bakarey, A., Opaleye, O., & Olaleye, D. (2011). Evaluation of immunity against poliovirus serotypes among children in riverine areas of Delta State, Nigeria. African Journal of Clinical and Experimental Microbiology, 12(2). https://doi.org/10.4314/ajcem.v12i2.64321