\begin{center} \begin{minipage}{0.7\textwidth} \selectlanguage{english} \chapter*{Abstract}
TODO
\end{minipage} \end{center} \blankpage \begin{center} \begin{minipage}{0.7\textwidth} \selectlanguage{ngerman} \chapter*{Zusammenfassung} \begin{otherlanguage}{ngerman}
\end{otherlanguage} \end{minipage} \end{center}