@article{PMF_1911_22_1_a7,
     author = {Sierpi\'nski, Wac{\l}aw},
     title = {Przyczynek do teoryi maxim\'ow i minim\'ow},
     journal = {Prace Matematyczno-Fizyczne},
     pages = {103--111},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {1911},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/PMF_1911_22_1_a7/}
}