@article{10_21136_CPM_1990_108363,
     author = {Zelinka, Bohdan},
     title = {Contraction distance between isomorphism classes of graphs},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky},
     pages = {211--216},
     year = {1990},
     volume = {115},
     number = {2},
     doi = {10.21136/CPM.1990.108363},
     mrnumber = {1054008},
     zbl = {0731.05016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPM.1990.108363/}
}