@article{CMUC_2009__50_4_a3,
     author = {Matou\v{s}ek, Milan and Pt\'ak, Pavel},
     title = {Symmetric difference on orthomodular lattices and $Z_2$-valued states},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {535--547},
     publisher = {mathdoc},
     volume = {50},
     number = {4},
     year = {2009},
     mrnumber = {2583131},
     zbl = {1212.06021},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_2009__50_4_a3/}
}