@article{CMFD_2012_45_a5,
     author = {M. Elin and M. Levenshtein and S. Reich and D. Shoikhet},
     title = {Some inequalities for the horosphere function and hyperbolically nonexpansive mappings on the {Hilbert} ball},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {75--93},
     publisher = {mathdoc},
     volume = {45},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2012_45_a5/}
}