A generalized transfer matrix is applied to calculate the reflectance of a semi-infinite periodic superlattice made up of spatially dispersive conducting layers, accounting for the propagation of plasma waves allowed by non-locality. The field inside the superlattice is written as a superposition of the two outgoing solutions of the bulk dispersion relation, with amplitudes given by the electromagnetic boundary conditions supplemented by additional boundary conditions. The discrepancies of the used formalism with that of Trutschel et al. are discussed
