@article{DAN_1973_212_6_a4,
     author = {A. V. Kozak},
     title = {A local principle in the theory of projection methods},
     journal = {Doklady Akademii Nauk},
     pages = {1287--1289},
     publisher = {mathdoc},
     volume = {212},
     number = {6},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_212_6_a4/}
}