Mustapha, U. T., Ahmad, Y. U., Yusuf, A., Qureshi, S., & Musa, S. S. (2023). Transmission dynamics of an age-structured Hepatitis-B infection with differential infectivity. Bulletin of Biomathematics, 1(2), 124–152. https://doi.org/10.59292/bulletinbiomath.2023007