@article{CMUC_1987__28_1_a15,
     author = {Pt\'ak, Pavel},
     title = {{\textquotedblleft}Hidden variables{\textquotedblright} on concrete logics (extensions)},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {157--163},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {1987},
     mrnumber = {889777},
     zbl = {0618.06005},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1987__28_1_a15/}
}