@article{DAN_1958_119_3_a4,
     author = {I. M. Glazman},
     title = {On the negative part of the spectrum of one-dimensional and multidimensional differential operators over vector-functions},
     journal = {Doklady Akademii Nauk},
     pages = {421--424},
     publisher = {mathdoc},
     volume = {119},
     number = {3},
     year = {1958},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_119_3_a4/}
}