@article{1029000216, author = {Wallen, Lawrence J.}, title = {A stability theorem for frames in Hilbert space.}, journal = {Michigan Math. J.}, volume = {16}, number = {1}, year = {1969}, pages = { 149-151}, language = {en}, url = {http://dml.mathdoc.fr/item/1029000216} }
Wallen, Lawrence J. A stability theorem for frames in Hilbert space.. Michigan Math. J., Tome 16 (1969) no. 1, pp. 149-151. http://gdmltest.u-ga.fr/item/1029000216/