%&LaTeX
\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{textcomp}

\begin{document}

\begin{thebibliography}{1}

\bibitem{Roesner_etal2016} R{\"o}sner, S., Senn, S., \& Englbrecht, C. (2016). Konsumereignisse w{\"a}hrend der station{\"a}ren Alkoholentw{\"o}hnung. \textit{SuchtMagazin}, \textit{42}(1), 35--38.

\end{thebibliography}

\end{document}

