@article{TRSPY_1986_173_a4,
     author = {V. I. Burenkov and E. M. Popova},
     title = {Improvement of extension operators by means of approximation operators that preserve boundary values},
     journal = {Informatics and Automation},
     pages = {50--54},
     publisher = {mathdoc},
     volume = {173},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1986_173_a4/}
}