@article{10_4064_cm_53_2_275_288,
     author = {Zbigniew Gajda},
     title = {Difference properties of higher orders for continuity and {Riemann} integrability},
     journal = {Colloquium Mathematicum},
     pages = {275--288},
     publisher = {mathdoc},
     volume = {53},
     number = {2},
     year = {1987},
     doi = {10.4064/cm-53-2-275-288},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-53-2-275-288/}
}