@article{702127,
     title = {Rough and strongly rough norms on Banach spaces},
     booktitle = {Abstracta. 7th Winter School on Abstract Analysis},
     series = {GDML\_Books},
     publisher = {Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1979},
     pages = {95-99},
     url = {http://dml.mathdoc.fr/item/702127}
}

Whitfield, J. H. M. Rough and strongly rough norms on Banach spaces, dans Abstracta. 7th Winter School on Abstract Analysis, GDML_Books,  (1979), pp. 95-99. http://gdmltest.u-ga.fr/item/702127/