@article{DE_1990_26_4_a18,
     author = {S. S. Titov},
     title = {Analyticity of linear one-parameter {Lie--B\"acklund} groups},
     journal = {Differencialʹnye uravneni\^a},
     pages = {699--702},
     publisher = {mathdoc},
     volume = {26},
     number = {4},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_4_a18/}
}