2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/109983We point out a general argument leading from the formula for currents through an open mesoscopic system given by the theory of non-equilibrium steady states (NESS) to the Landauer-Büttiker formula.8 pages, changes in the introductory part, reference and note addedMathematical Physicstext