@article{CMUC_1965_6_4_a4,
     author = {Chv\'atal, Va\v{s}ek},
     title = {On finite and countable rigid graphs and tournaments},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {429--438},
     year = {1965},
     volume = {6},
     number = {4},
     mrnumber = {0190023},
     zbl = {0132.21401},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1965_6_4_a4/}
}