Componentwise Error Bounds and Direct Linear System Solving. - Beat Hörmann; Christian P. Ullrich (WNAA, 1996)

Verification May be Better than Estimation. - C. Falcó Korn; Beat Hörmann; Christian P. Ullrich (SIAM J. Sci. Comput., 1996)

Error assessment with approximate inverses in linear system solving with application to stopping criteria for iterative methods. - Beat Hörmann (Shaker, 1997)