%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Martin_etal1991} {\textquotedblleft}\textit{Ab initio study of the structure, infrared spectra and heat of formation of C$_{4}$}{\textquotedblright}. Martin JML, Fran{\c c}ois JP, Gijbels R, The journal of chemical physics \textbf{94}, 3753 (1991)

\end{thebibliography}

\end{document}

