Fractional-calculus analysis of the dynamics of T cells and human immunodeficiency virusesAbdulrahman Obaid Alshammari, Imtiaz Ahmad, Rashid Jan and Sahar Ahmed IdrisEur. Phys. J. Spec. Top., (2024) 1-13DOI: https://doi.org/10.1140/epjs/s11734-024-01192-5