@article{GDZPPN002347393, title = {Unbounded Soboleff Regions.}, journal = {Mathematica Scandinavica}, volume = {13}, year = {1963}, pages = {75-89}, zbl = {0131.32604}, url = {http://dml.mathdoc.fr/item/GDZPPN002347393} }
Andersson, Rolf. Unbounded Soboleff Regions.. Mathematica Scandinavica, Tome 13 (1963) pp. 75-89. http://gdmltest.u-ga.fr/item/GDZPPN002347393/