@article{ETNA_1999__8__a7,
     author = {Bj\"orck, \r{A}ke and Yuan, J.Y.},
     title = {Preconditioners for least squares problems by {LU} factorization},
     journal = {Electronic transactions on numerical analysis},
     pages = {26--35},
     publisher = {mathdoc},
     volume = {8},
     year = {1999},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_1999__8__a7/}
}