@unpublished{BeckersBehrensWollner2017, author = {Susanne Beckers and J{\"o}rn Behrens and Winnifried Wollner}, title = {Duality Based Error Estimation in the Presence of Discontinuities}, institution = {Technische Universit{\"a}t Darmstadt}, pages = {21}, year = {2017}, }