@article{DAN_1979_247_5_a18,
     author = {A. V. Zhiber and A. B. Shabat},
     title = {The {Klein{\textendash}Gordon} equation with nontrivial group},
     journal = {Doklady Akademii Nauk},
     pages = {1103--1107},
     year = {1979},
     volume = {247},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1979_247_5_a18/}
}