\documentclass[a4paper]{article}
\usepackage[margin=25mm]{geometry}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{amsmath}

\title{Title of contribution (talk, poster or online poster)}
\author{Author Surname$^{1}$, Someone Else$^{2}$  \\
        \small $^{1}$University A \\
        \small $^{2}$University B \\
}
\date{e-mail@mail.com} % speaker email  

% Please do not add any other package!!!
% Please do not add any figure!!!
% If you have any question about latex template please contact us info@ecmtb2020.org

\begin{document}
\maketitle

Abstract of your contribution. You can use math $1+2=3$ and references in a simple format, i.e. \\

{\bf References}
\newline
[1] A.U. Thor and S. Author, Title of book, publisher, year. 
\newline
[2] A.U. Thor and S. Author, Title of article, journal, volume(number):pages, year.


\end{document}