Preconditioners for saddle point linear systems with highly singular ( 1 , 1 ) blocks. Greif, Chen; Schötzau, Dominik — 2006 ETNA. Electronic Transactions on Numerical Analysis [electronic only]
An analysis of low-rank modifications of preconditioners for saddle point systems. Greif, Chen; Overton, Michael L. — 2010 ETNA. Electronic Transactions on Numerical Analysis [electronic only]