@article{10_4064_ap_7_1_33_40,
     author = {K. Urbanik},
     title = {On a problem of {S.L.} {Cheng} concerning sequences of functions with convergent k-th differences},
     journal = {Annales Polonici Mathematici},
     pages = {33--40},
     publisher = {mathdoc},
     volume = {7},
     number = {1},
     year = {1959},
     doi = {10.4064/ap-7-1-33-40},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-7-1-33-40/}
}