\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 $^\flat$,\\
		\normalsize Address of Institution$^\flat$.\\ 
		\normalsize ($\natural$)\; Name of Institution $^\natural$,\\
		\normalsize Address of Institution $^\natural$. \\
		\normalsize ($\diamondsuit$)\; Name of Institution $^\diamondsuit$,\\
		\normalsize Address of Institution $^\diamondsuit$. \\
\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}