@article{MM_2004_16_3_a10,
     author = {N. N. Kalitkin and L. V. Kuzmina},
     title = {On approximation with nonorthogonal systems},
     journal = {Matemati\v{c}eskoe modelirovanie},
     pages = {95--108},
     publisher = {mathdoc},
     volume = {16},
     number = {3},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MM_2004_16_3_a10/}
}