%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Semenov_etal2007} {\textquotedblleft}\textit{Assessing the size-dependent chemical speciation of soil particles using electron probe X-ray microanalysis}{\textquotedblright}. Semenov MY, Spolnik Z, Van Grieken R, Microchimica acta \textbf{157}, 121 (2007).   http://doi.org/10.1007/S00604-006-0637-3

\end{thebibliography}

\end{document}

