Continuity and boundary conditions in thermodynamics: From Carnot's efficiency to efficiencies at maximum powerH. Ouerdane, Y. Apertet, C. Goupil and Ph. LecoeurEur. Phys. J. Special Topics, 224 5 (2015) 839-864DOI: https://doi.org/10.1140/epjst/e2015-02431-x