1. Iterative methods for elliptic difference equations;Fedorenko;Russ. Math. Surv.,1973
2. Multigrid;Trottenberg,2000
3. A Multigrid Tutorial;Briggs,2000
4. Multigrid solutions to elliptic flow problems;Brandt,1979
5. Multigrid methods for hyperbolic equations;Katzer,1991