@article{701243,
     title = {On flatness and some ergodic properties of Banach spaces},
     booktitle = {Abstracta. 9th Winter School on Abstract Analysis},
     series = {GDML\_Books},
     publisher = {Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1981},
     pages = {138-142},
     url = {http://dml.mathdoc.fr/item/701243}
}

Pach, A. J. On flatness and some ergodic properties of Banach spaces, dans Abstracta. 9th Winter School on Abstract Analysis, GDML_Books,  (1981), pp. 138-142. http://gdmltest.u-ga.fr/item/701243/