Thermal Casimir effect with general boundary conditions J. M. Muñoz-Castañeda, L. Santamaría-Sanz, M. Donaire and M. Tello-Fraile Eur. Phys. J. C, 80 8 (2020) 793 Published online: 29 August 2020 DOI: 10.1140/epjc/s10052-020-8348-1