%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Thomas_etal2012} Thomas, K. V., Bijlsma, L., Castiglioni, S., Covaci, A., Emke, E., Grabic, R., et al. (2012). Comparing illicit drug use in 19 European cities through sewage analysis. \textit{Science of the Total Environment}, \textit{432}, 432--439.

\end{thebibliography}

\end{document}

