@article{TMF_1988_76_1_a7,
     author = {E. I. Shulman},
     title = {Additional integrals of the motion of classical {Hamiltonian} wave systems},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {88--99},
     publisher = {mathdoc},
     volume = {76},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1988_76_1_a7/}
}