@article{BUMI_2001_8_4B_3_a5,
     author = {Crupi, Marilena and Restuccia, Gaetana},
     title = {Iterative differentiations in rings of unequal characteristic},
     journal = {Bollettino della Unione matematica italiana},
     pages = {635--646},
     publisher = {mathdoc},
     volume = {Ser. 8, 4B},
     number = {3},
     year = {2001},
     zbl = {1177.13018},
     mrnumber = {1481587},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BUMI_2001_8_4B_3_a5/}
}