@misc{WM_1908_12_Dodatek_1_a2,
     title = {Pewnik i postulat},
     journal = {Wiadomo\'sci Matematyczne},
     pages = {21--30},
     publisher = {mathdoc},
     volume = {12},
     number = {Dodatek_1},
     year = {1908},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/WM_1908_12_Dodatek_1_a2/}
}