@article{1077380584,
author = {Halmos, P. R.},
title = {Products of shifts},
journal = {Duke Math. J.},
volume = {39},
number = {1},
year = {1972},
pages = { 779-787},
language = {en},
url = {http://dml.mathdoc.fr/item/1077380584}
}
Halmos, P. R. Products of shifts. Duke Math. J., Tome 39 (1972) no. 1, pp. 779-787. http://gdmltest.u-ga.fr/item/1077380584/