%0 Journal Article %A S. A. Nazarov %T Asymptotics of eigenvalues in spectral gaps of periodic waveguides with small singular perturbations %J Zapiski Nauchnykh Seminarov POMI %D 2018 %P 168-210 %V 471 %I mathdoc %U http://geodesic.mathdoc.fr/item/ZNSL_2018_471_a11/ %G ru %F ZNSL_2018_471_a11