@article{JMAG_2006_2_2_a5,
     author = {Ye. V. Petrov},
     title = {The {Gauss} map of hypersurfaces in 2-step nilpotent lie groups},
     journal = {\v{Z}urnal matemati\v{c}eskoj fiziki, analiza, geometrii},
     pages = {186--206},
     year = {2006},
     volume = {2},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JMAG_2006_2_2_a5/}
}