@article{10_21136_CMJ_1970_100948,
     author = {Frol{\'\i}k, Zden\v{e}k},
     title = {A separation theorem and applications to {Borel} sets},
     journal = {Czechoslovak Mathematical Journal},
     pages = {98--108},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {1970},
     doi = {10.21136/CMJ.1970.100948},
     mrnumber = {0266133},
     zbl = {0221.54033},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1970.100948/}
}