@article{TMF_1983_54_2_a4,
     author = {A. P. Isaev},
     title = {Integrals of the motion of a~closed relativistic string},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {209--218},
     year = {1983},
     volume = {54},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1983_54_2_a4/}
}