@article{DAN_1973_212_2_a9,
     author = {A. V. Sobolev},
     title = {A certain class of positive linear operators in topological linear spaces},
     journal = {Doklady Akademii Nauk},
     pages = {305--307},
     publisher = {mathdoc},
     volume = {212},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_212_2_a9/}
}