@article{DAN_1991_316_4_a30,
     author = {V. A. Dzhrbashyan},
     title = {On essential positivity of electron energies in relativistic theory. {Realistic
}},
     journal = {Doklady Akademii Nauk},
     pages = {897--899},
     publisher = {mathdoc},
     volume = {316},
     number = {4},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_316_4_a30/}
}