@article{SM_2006_197_1_a2,
     author = {M. I. Zelikin},
     title = {Geometry of operator cross ratio},
     journal = {Sbornik. Mathematics},
     pages = {37--51},
     publisher = {mathdoc},
     volume = {197},
     number = {1},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2006_197_1_a2/}
}