@article{CMUC_1968_9_1_a5,
     author = {Hell, Pavol},
     title = {Rigid undirected graphs with given number of vertices},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {51--69},
     year = {1968},
     volume = {9},
     number = {1},
     mrnumber = {0229542},
     zbl = {0167.22101},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1968_9_1_a5/}
}