@article{DAN_1979_244_2_a0,
     author = {M. Wollenberg and V. D. Koshmanenko},
     title = {On the structure of wave operators},
     journal = {Doklady Akademii Nauk},
     pages = {265--269},
     publisher = {mathdoc},
     volume = {244},
     number = {2},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_244_2_a0/}
}