[en] Plasma oscillations in multi-layer and two-dimensional superlattices (MLS and TDS) are considered. MLS and TDS are made by an infinite system of ''electron planes'' immersed into a dielectric medium. TDS occurs in inversion MLS channels of structures on surfaces slightly deviated from singular directions. A spectrum of two-dimensional plasma waves which in MLS consists of one band without provision for interaction with sound. While taking into account interaction with sound through piesoeffect in MLS an infinite sequence of bands with plasma-acoustic oscillations occurs. In case of TDS the spectrum of both plasma oscillations and surface elastic waves has a multiband character