Voir la notice de l'article provenant de la source Math-Net.Ru
@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/} }
B. M. Gagaev. Certain properties of orthogonal systems of functions. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 12 (1972), pp. 40-45. http://geodesic.mathdoc.fr/item/IVM_1972_12_a3/