Umar H, A., Aisha, H.Z., Hussaini, I.H., and Aliyu, M.S., “Seroprevalence and Risk Factors Associated with Hepatitis B Virus Infection among Pregnant Women Attending Antenatal Care in Azare, Bauchi State, Nigeria”, UJMR, vol. 5, no. 1, pp. 9–17, Jun. 2020.