@article{GDZPPN002343827, title = {Problem 12}, journal = {Mathematica Scandinavica}, volume = {3}, year = {1955}, pages = {171-171}, zbl = {0065.30303}, url = {http://dml.mathdoc.fr/item/GDZPPN002343827} }
BEURLING, ARNE. Problem 12. Mathematica Scandinavica, Tome 3 (1955) p. 171. http://gdmltest.u-ga.fr/item/GDZPPN002343827/