@article{hal-01333722, author = {Haar, Alfred}, title = {Zur Theorie der orthogonalen Funktionensysteme}, journal = {HAL}, volume = {1910}, number = {0}, year = {1910}, language = {de}, url = {http://dml.mathdoc.fr/item/hal-01333722} }
Haar, Alfred. Zur Theorie der orthogonalen Funktionensysteme. HAL, Tome 1910 (1910) no. 0, . http://gdmltest.u-ga.fr/item/hal-01333722/