@article{AA_2002_14_6_a1,
     author = {A. Vagharshakyan},
     title = {Linear causal filters and weighted polynomial approximation},
     journal = {Algebra i analiz},
     pages = {89--100},
     year = {2002},
     volume = {14},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_2002_14_6_a1/}
}