@article{PMF_1888_1_1_a7,
     author = {Ptaszycki, J.},
     title = {O ca{\l}kowaniu algebraiczn\'em r\'o\.zniczek algebraicznych},
     journal = {Prace Matematyczno-Fizyczne},
     pages = {81--90},
     publisher = {mathdoc},
     volume = {1},
     number = {1},
     year = {1888},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/item/PMF_1888_1_1_a7/}
}