@article{IVM_1972_12_a3,
     author = {B. M. Gagaev},
     title = {Certain properties of orthogonal systems of functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {40--45},
     publisher = {mathdoc},
     number = {12},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1972_12_a3/}
}