@misc{WM_1908_12_Dodatek_2_a1,
     title = {Dow\'od elementarny pewnego wzoru z {Analizy}},
     journal = {Wiadomo\'sci Matematyczne},
     pages = {71--75},
     publisher = {mathdoc},
     volume = {12},
     number = {Dodatek_2},
     year = {1908},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/WM_1908_12_Dodatek_2_a1/}
}