@article{ZNSL_1986_149_a13,
     author = {S. Z. Rafal'son},
     title = {Generalized shift, generalized convolution and some extremal relations of the theory of approximation of function},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {150--157},
     publisher = {mathdoc},
     volume = {149},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1986_149_a13/}
}