@article{IM2_2014_78_4_a5,
     author = {E. A. Neganova and V. I. Trofimov},
     title = {Symmetrical extensions of graphs},
     journal = {Izvestiya. Mathematics},
     pages = {809--835},
     year = {2014},
     volume = {78},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2014_78_4_a5/}
}