@article{10_4153_CMB_1999_004_5,
     author = {Christensen, Ole},
     title = {Operators with {Closed} {Range,} {Pseudo-Inverses,} and {Perturbation} of {Frames} for a {Subspace}},
     journal = {Canadian mathematical bulletin},
     pages = {37--45},
     year = {1999},
     volume = {42},
     number = {1},
     doi = {10.4153/CMB-1999-004-5},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1999-004-5/}
}