Walter Zulehner,
"Efficient solvers for saddle point solvers with applications to PDE-constrained optimization"
, in T. Apel and O. Steinbach: Advanced Finite Element Methods and Applications, Springer, Heidelberg, New York, Seite(n) 197 - 216, 2013
Original Titel:
Efficient solvers for saddle point solvers with applications to PDE-constrained optimization