@article{ZNSL_2015_440_a5,
     author = {V. V. Zhuk},
     title = {On strong approximation of functions by positive operators},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {68--80},
     publisher = {mathdoc},
     volume = {440},
     year = {2015},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2015_440_a5/}
}