@article{MZM_1979_26_5_a5,
     author = {T. V. Andreeva},
     title = {Orthogonality of elements to~a sum of subspaces},
     journal = {Matemati\v{c}eskie zametki},
     pages = {699--711},
     publisher = {mathdoc},
     volume = {26},
     number = {5},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1979_26_5_a5/}
}