@article{SM_2012_203_4_a4,
     author = {S. I. Bogataya and S. A. Bogatyi and E. A. Kudryavtseva},
     title = {An inverse theorem on `economic' maps},
     journal = {Sbornik. Mathematics},
     pages = {554--568},
     publisher = {mathdoc},
     volume = {203},
     number = {4},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2012_203_4_a4/}
}