@article{ZNSL_2020_491_a4,
     author = {L. N. Ikhsanov},
     title = {Exact estimates of approximation by abstract {Kantorovich} type operators in terms of the second modulus of continuity},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {66--93},
     year = {2020},
     volume = {491},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2020_491_a4/}
}