@article{PDM_2017_1_a7,
     author = {Y. E. Avezova and V. M. Fomichev},
     title = {Conditions of primitivity and exponent bounds for sets of digraphs},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {89--101},
     publisher = {mathdoc},
     number = {1},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2017_1_a7/}
}