@article{DAN_1977_236_4_a4,
     author = {A. A. Laptev},
     title = {Spectral asymptotics of a composition of pseudodifferential operators and reflections from the boundary},
     journal = {Doklady Akademii Nauk},
     pages = {800--803},
     publisher = {mathdoc},
     volume = {236},
     number = {4},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_236_4_a4/}
}