@article{TMF_1990_82_1_a9,
     author = {V. M. Shabaev},
     title = {Rayleigh{\textendash}Schr\"odinger perturbation theory for a~relativistic atom},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {83--89},
     year = {1990},
     volume = {82},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1990_82_1_a9/}
}