@article{CMUC_1986__27_4_a14,
     author = {Ml\v{c}ek, Josef},
     title = {$\beta$-structures},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {765--773},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1986},
     mrnumber = {874671},
     zbl = {0617.03037},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1986__27_4_a14/}
}