@article{TRSPY_1992_194_a8,
     author = {P. I. Lizorkin},
     title = {Direct and inverse theorems of approximation theory for functions on {Lobachevsky} space},
     journal = {Informatics and Automation},
     pages = {120--147},
     publisher = {mathdoc},
     volume = {194},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1992_194_a8/}
}