@article{ZVMMF_1974_14_2_a16,
     author = {G. Ts. Akopyan},
     title = {Covers and joins of the vertices of a graph by edges},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {461--469},
     publisher = {mathdoc},
     volume = {14},
     number = {2},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1974_14_2_a16/}
}