\documentclass[a4paper,11pt]{book}
% Some usual packages
\usepackage[utf8]{inputenc}
\usepackage{geometry}
\geometry{
a4paper,
left=20mm,
top=15mm,
bottom=20mm,
}
\usepackage[hidelinks]{hyperref}
\usepackage{titlesec}
\usepackage{etoolbox}
\patchcmd{\thebibliography}{\chapter*}{\section*}{}{}
\renewcommand{\bibname}{References}
\bibliographystyle{plainnat}
\usepackage{graphicx}
\usepackage{lipsum}
\usepackage{xcolor}
\usepackage{amsbsy,amsmath,amssymb,amsfonts,amssymb}
\pagestyle{empty}
\begin{document}
\titleformat{\chapter}[frame]{\normalfont}{}{10pt}{\LARGE\bfseries\filcenter}
\chapter{Title of the abstract}
\thispagestyle{empty}
\vspace{-0.5cm}
\begin{center}
\begin{large}
A. Author $^\flat$,\footnote{email@correspondingauthor}
B. Author$^\natural$
and C. Author$^\diamondsuit$\\
\vspace{0.25cm}
\normalsize ($\flat$)\; Name of Institution,\\
\normalsize Address of Institution.\\
\normalsize ($\natural$)\; Name of Institution,\\
\normalsize Address of Institution. \\
\normalsize ($\diamondsuit$)\; Name of Institution,\\
\normalsize Address of Institution. \\
\end{large}
\end{center}
\vspace{-0.5cm}
\section*{Abstract}
Present your work.
\begin{small}
\begin{thebibliography}{99}
\bibitem{Paper}
AutorA, A., AutorB, B., Title of the paper
{\em Name of the Journal}, Volume(Number):Initial Page--Final Page, Year.
\bibitem{Book} BookAuthor, A., Title of the Book. City, Editorial, Year.
\end{thebibliography}
\end{small}
\end{document}
