@article{MASLO_1980_30_4_a9,
     author = {Akiyama, Jin and Exoo, Geoffrey and Harary, Frank},
     title = {Covering and packing in graphs. {III:} {Cyclic} and acyclic invariants},
     journal = {Mathematica slovaca},
     pages = {405--417},
     year = {1980},
     volume = {30},
     number = {4},
     mrnumber = {595302},
     zbl = {0458.05050},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1980_30_4_a9/}
}