\documentclass[a4paper]{article}
\pagestyle{headings}
%\usepackage{graphicx}
\usepackage{amssymb,amsmath}
%\usepackage{hyperref}
%\usepackage{picins}


\title{...}
\author{...}


\begin{document}
\maketitle

\begin{abstract}
...
\end{abstract}

\section{Introduction}




\begin{thebibliography}{}


\end{thebibliography}

\end{document}

