%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Davila_etal2013} D{\'a}vila, P., K{\"u}lls, C., \& Weiler, M. (2013). A toolkit for groundwater mean residence time interpretation with gaseous tracers. \textit{Computers \& Geosciences}, \textit{61}, 116--125.

\end{thebibliography}

\end{document}

