@article{GDZPPN002098598, title = {An Example on the Heisenberg Group Related to the Levy Operator.}, journal = {Inventiones mathematicae}, volume = {69}, year = {1982}, pages = {209-216}, zbl = {0515.58032}, url = {http://dml.mathdoc.fr/item/GDZPPN002098598} }
Stein, E.M. An Example on the Heisenberg Group Related to the Levy Operator.. Inventiones mathematicae, Tome 69 (1982) pp. 209-216. http://gdmltest.u-ga.fr/item/GDZPPN002098598/