@techreport{LubkollSchielaWeiser2015, author = {Lars Lubkoll and Anton Schiela and Martin Weiser}, title = {An affine covariant composite step method for optimization with PDEs as equality constraints}, institution = {ZIB}, address = {Takustr. 7, 14195 Berlin}, number = {15-09}, language = {eng}, year = {2015} }