@article{CMUC_1981__22_4_a7,
     author = {Koubek, V\'aclav and R\"odl, Vojt\v{e}ch},
     title = {On number of covering arcs in orderings},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {721--733},
     publisher = {mathdoc},
     volume = {22},
     number = {4},
     year = {1981},
     mrnumber = {647020},
     zbl = {0483.05035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1981__22_4_a7/}
}