@article{FAA_1980_14_1_a3,
     author = {N. Kh. Ibragimov and A. B. Shabat},
     title = {Evolutionary equations with nontrivial {Lie{\textendash}B\"acklund} group},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {25--36},
     year = {1980},
     volume = {14},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1980_14_1_a3/}
}