%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Walkiewicz_etal2016} Walkiewicz, A., Bulak, P., Brzezinska, M., Wnuk, E., \& Bieganowski, A. (2016). Methane oxidation in heavy metal contaminated Mollic Gleysol under oxic and hypoxic conditions. \textit{Environ. Pollut.}, \textit{213}, 403--411.

\end{thebibliography}

\end{document}

