Null geodesics in five-dimensional Reissner–Nordström anti-de Sitter black holesP. A. González, Marco Olivares, Yerko Vásquez and J. R. VillanuevaEur. Phys. J. C, 81 3 (2021) 236DOI: https://doi.org/10.1140/epjc/s10052-021-09024-9