@article{GDZPPN002298244, title = {On the Structure of the Infinite Dimensional Unitary Group}, journal = {Mathematische Annalen}, volume = {174}, year = {1967}, pages = {197-202}, zbl = {0146.25506}, url = {http://dml.mathdoc.fr/item/GDZPPN002298244} }
Spiegel, E. On the Structure of the Infinite Dimensional Unitary Group. Mathematische Annalen, Tome 174 (1967) pp. 197-202. http://gdmltest.u-ga.fr/item/GDZPPN002298244/