@misc{WM_1902_6_1-2-3_a0,
     title = {Eugeniusz {Beltrami}},
     journal = {Wiadomo\'sci Matematyczne},
     pages = {1--55},
     publisher = {mathdoc},
     volume = {6},
     number = {1-2-3},
     year = {1902},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/WM_1902_6_1-2-3_a0/}
}