@article{TMF_1977_32_3_a3,
     author = {V. S. Popov},
     title = {Invariant operators for the classical groups},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {344--347},
     publisher = {mathdoc},
     volume = {32},
     number = {3},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1977_32_3_a3/}
}