@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/