@article{RM_1991_46_4_a7,
     author = {R. F. Galeeva and N. I. Chernov},
     title = {Conditions of strict exponential growth of the number of cycles in countable directed graphs},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {172--173},
     publisher = {mathdoc},
     volume = {46},
     number = {4},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1991_46_4_a7/}
}