1. Antil, H., Hoppe, R.H.W., Linsenmann, C.: Path-following primal-dual interior point methods for shape optimization of stationary flow problems. J. Numer. Math. 11, 81–100 (2007)
2. Ascher, U., Haber, E.: A multigrid method for distributed parameter estimation problems. ETNA 18, 1–18 (2003)
3. Borzi, A., Kunisch, K., Kwak, D.Y.: Accuracy and convergence properties of the finite difference multigrid solution of an optimal control optimality system. SIAM J. Control Opt. 41(5), 1477–1497 (2004)
4. Borzi, A., Schulz, V.: Multigrid methods for PDE optimization. SIAM Rev. (2007) (to appear)
5. Braess, D., Sarazin, R.: An efficient smoother for the Stokes problem. Appl. Numer. Math. 23, 3–19 (1996)