@article{IM2_1987_29_2_a7,
     author = {V. I. Trofimov},
     title = {The action of a~group on a~graph},
     journal = {Izvestiya. Mathematics },
     pages = {429--447},
     publisher = {mathdoc},
     volume = {29},
     number = {2},
     year = {1987},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1987_29_2_a7/}
}