1. B. L. Buzbee, G. H. Golub, and C.W. Nielson, “On direct methods for solving Poisson’s equation,” SIAM J. Numer. Anal. 7 (1970), pp. 627–656.
2. P. Concus and G.H. Golub, “Use of fast direct methods for the efficient numerical solution of nonseparable elliptic equations,” SIAM J. Numer. Anal. 10 (1973), pp. 1103–1120.
3. P. Concus, G.H. Golub, and D.P. O’Leary, “A generalized conjugate gradient method for the numerical solution of elliptic partial differential equations,” Proc. Symposium on Sparse Matrix Computations, Argonne National Lab., Sept. 1975, Academic Press (to appear).
4. G. H. Golub, “The use of Chebyshev matrix polynomials in the iterative solution of linear equations compared with the method of successive over-relaxation,” Ph.D. Thesis, University of Illinois. 1959.
5. G.H. Golub and R.S. Varga, “Chebyshev semi-iterative methods, successive over-relaxation iterative methods, and second order Richardson iterative methods,” Numer. Math. 3 (1961), pp. 147–168.