@article{PMF_1912_23_1_a0,
     author = {Sierpi\'nski, Wac{\l}aw},
     title = {Przyczynek do r\'o\.zniczkowalno\'sci funkcyj},
     journal = {Prace Matematyczno-Fizyczne},
     pages = {1--11},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {1912},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/PMF_1912_23_1_a0/}
}