%&LaTeX
\documentclass{article}

\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{textcomp}

\begin{document}

\begin{thebibliography}{10}

\bibitem{Ruenger1935} R{\"u}nger, F. (1935). \textit{{\"U}ber die Ern{\"a}hrung des Alands (Idus melanotus H.)} (Vol. 33).

\end{thebibliography}

\end{document}

