\documentclass[a4paper,11pt]{article}
\usepackage{latexsym}
\author{A. Einstein}
\title{The theory of relativity}
\date{June, 1905}
\begin{document}
\maketitle \tableofcontents
\section{Introduction}
 The Gallilean invariance holds for the Newton
 equations of motion but it does not hold in the case
 of Maxwell’s equations.The Gallilean invariance holds for the Newton
 equations of motion but it does not hold in the case
 of Maxwell’s equations.The Gallilean invariance holds for the Newton
 equations of motion but it does not hold in the case
 of Maxwell’s equations.The Gallilean invariance holds for the Newton
 equations of motion but it does not hold in the case
 of Maxwell’s equations.The Gallilean invariance holds for the Newton
 equations of motion but it does not hold in the case
 of Maxwell’s equations.

 \begin{equation}
F=m\gamma
\end{equation}
 \begin{equation}
 \int_0^{2a}f(x)dx = b  \label{inte}
\end{equation}
\section{Conclusions}
We showed that there exists an upper bound to all velocities and
that this bound is the speed of light in vacuum, see equation We
showed that there exists an upper bound to all velocities and that
this bound is the speed of light in vacuum, see equation We showed
that there exists an upper bound to all velocities and that this
bound is the speed of light in vacuum, see equation We showed that
there exists an upper bound to all velocities and that this bound
is the speed of light in vacuum, see equation We showed that there
exists an upper bound to all velocities and that this bound is the
speed of light in vacuum, see equation We showed that there exists
an upper bound to all velocities and that this bound is the speed
of light in vacuum, see equation \ref{inte}.
\end{document}
