@article{GDZPPN002344149, title = {Problem 16}, journal = {Mathematica Scandinavica}, volume = {3}, year = {1955}, pages = {306-306}, url = {http://dml.mathdoc.fr/item/GDZPPN002344149} }
PLEIJEL, ARNE. Problem 16. Mathematica Scandinavica, Tome 3 (1955) p. 306. http://gdmltest.u-ga.fr/item/GDZPPN002344149/