%&LaTeX
\documentclass{article}

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

\begin{document}

\begin{thebibliography}{1}

\bibitem{Reig_etal2017} Reig, M., Valle, J. W. F., \& Vaquera-Araujo, C. A. (2017). Unifying left-right symmetry and 331 electroweak theories. \textit{Phys. Lett. B}, \textit{766}, 35--40.

\end{thebibliography}

\end{document}

