@article{DOCMA_2009__14__a7,
     author = {Popescu, Gelu},
     title = {Hyperbolic geometry on noncommutative balls},
     journal = {Documenta mathematica},
     pages = {595--651},
     publisher = {mathdoc},
     volume = {14},
     year = {2009},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DOCMA_2009__14__a7/}
}