@article{AM2_1991__42_3_137425,
     author = {K.J. Heuvers and B.R. Ebanks and C.T. Ng},
     title = {On {Cauchy} differences of all orders.},
     journal = {Aequationes mathematicae},
     pages = {137--153},
     year = {1991},
     volume = {42},
     number = {3},
     zbl = {0744.39003},
     url = {http://geodesic.mathdoc.fr/item/AM2_1991__42_3_137425/}
}