@article{CMUC_1979__20_4_a2,
     author = {\v{C}uda, Karel and Vop\v{e}nka, Petr},
     title = {Real and imaginary classes in the alternative set theory},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {639--653},
     publisher = {mathdoc},
     volume = {20},
     number = {4},
     year = {1979},
     mrnumber = {555180},
     zbl = {0433.03031},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1979__20_4_a2/}
}