%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Welton_etal2004} Welton, A., Adelberger, K., Patterson, K., \& Gilbert, D. (2004). Optimal placement of syringe-exchange programs : abstract. \textit{Journal of urban health : bulletin of the New York Academy of Medicine}, \textit{81}(2), 1.

\end{thebibliography}

\end{document}

