\def \frameTitle {Managementstile}

\begin{frame}{\frameTitle}
   \begin{tikzpicture}
        \useasboundingbox (0,0) rectangle(\textwidth,0.8\textheight);
        \node [below right] (text) at (current bounding box.north west){
            \begin{minipage}[t]{\linewidth}
            \end{minipage} 
        };
        \node[above right] at (current bounding box.south west) {
            \begin{minipage}[t]{\linewidth}
                \tiny
                \textbf{Quellen:}\\
            \end{minipage}
        };
   \end{tikzpicture}
\end{frame}