1. “Solution of linear systems of equations: iterative methods”;Axelsson,1977
2. “A modified upwind scheme for convective transport equation and the use of the conjugate gradient method for the solution of nonsymmetric systems of equations”;Axelsson,1977
3. “A conjugate gradient approach to nonlinear elliptic boundary value problems in irregular regions”;Bartels,1973
4. “Implicit alternating direction methods”;Birkhoff;Trans. Amer. Math. Soc.,1959
5. “Alternating direction implicit methods”;Birkhoff;Advances in Computers,1962