@article{DMGT_2003_23_1_a3,
     author = {Sonntag, Martin},
     title = {Difference labelling of cacti},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {55--65},
     year = {2003},
     volume = {23},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2003_23_1_a3/}
}