@article{JMAG_2010_6_3_a3,
     author = {A. Il'inskii},
     title = {On a question by {A.} {M.~Kagan}},
     journal = {\v{Z}urnal matemati\v{c}eskoj fiziki, analiza, geometrii},
     pages = {291--294},
     year = {2010},
     volume = {6},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/JMAG_2010_6_3_a3/}
}