@article{SJIM_1999_2_2_a3,
     author = {H. Ya. Bulgakov and V. L. Vaskevich},
     title = {Hierarchical bases in {Hilbert} spaces},
     journal = {Sibirskij \v{z}urnal industrialʹnoj matematiki},
     pages = {24--35},
     publisher = {mathdoc},
     volume = {2},
     number = {2},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJIM_1999_2_2_a3/}
}