@article{TMF_1993_94_2_a4,
     author = {H. J. de Vega and A. V. Mikhailov and N. S\'anchez},
     title = {Exact string solutions in $2+1$-dimensional de {Sitter} spacetime},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {232--240},
     year = {1993},
     volume = {94},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1993_94_2_a4/}
}