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@article{CM_1937__4__373_0, author = {Sidon, S.}, title = {\"Uber unvollst\"andige {Orthogonalsysteme}}, journal = {Compositio Mathematica}, pages = {373--379}, publisher = {Johnson Reprint Corporation}, volume = {4}, year = {1937}, zbl = {0016.30003}, language = {de}, url = {http://geodesic.mathdoc.fr/item/CM_1937__4__373_0/} }
Sidon, S. Über unvollständige Orthogonalsysteme. Compositio Mathematica, Tome 4 (1937), pp. 373-379. http://geodesic.mathdoc.fr/item/CM_1937__4__373_0/