James R. Bunch Richard C. Le Borne Ian K. Proudler Analysis of the direct and indirect <i>a posteriori</i> RLSL algorithm. 453-466 2001 8 Numer. Linear Algebra Appl. 6-7 https://doi.org/10.1002/nla.249 db/journals/nla/nla8.html#BunchBP01