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@article{IVM_2002_4_a3, author = {M. G. Grigoryan}, title = {On an orthonormal system}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {24--28}, publisher = {mathdoc}, number = {4}, year = {2002}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_2002_4_a3/} }
M. G. Grigoryan. On an orthonormal system. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 4 (2002), pp. 24-28. http://geodesic.mathdoc.fr/item/IVM_2002_4_a3/