%0 Journal Article %A S. A. Nazarov %T Waveguide with double threshold~resonance at a~simple threshold %J Sbornik. Mathematics %D 2020 %P 1080-1126 %V 211 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_2020_211_8_a1/ %G en %F SM_2020_211_8_a1