@article{TMF_1980_42_1_a14,
     author = {G. A. Kotel'nikov},
     title = {Group properties of~the wave equation with noninvariant velocity of~light},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {139--144},
     publisher = {mathdoc},
     volume = {42},
     number = {1},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1980_42_1_a14/}
}