@article {14157,
	title = {Preconditioning by Fast Direct Methods for Nonself-Adjoint Nonseparable Elliptic Equations},
	journal = {SIAM Journal on Numerical Analysis},
	volume = {23},
	year = {1986},
	month = {1986/02/01/},
	pages = {44 - 57},
	abstract = {We consider the use of fast direct methods as preconditioners for iterative methods for computing the numerical solution of nonself-adjoint elliptic boundary value problems. We derive bounds on convergence rates that are independent of discretization mesh size. For two-dimensional problems on rectangular domains, discretized on an n {\texttimes} n grid, these bounds lead to asymptotic operation counts of O(n<sup>2</sup> log n log ε<sup>-1</sup>) to achieve relative error ε and O(n<sup>2</sup>(log n)<sup>2</sup>) to reach truncation error.},
	isbn = {0036-1429},
	url = {http://www.jstor.org/stable/2157450},
	author = {Elman, Howard and Schultz, Martin H.}
}
