%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Kuells+Bassukas2022} K{\"u}lls, C., \& Bassukas, D. (2022). Groundwater salinization dynamics-an isotope approach. In \textit{EGU General Assembly Conference Abstracts} (22).

\end{thebibliography}

\end{document}

