\documentclass[12pt]{article}
\usepackage{graphicx}

\usepackage{latexsym}
\usepackage{url}

\usepackage{a4wide}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{listings}
\usepackage{fancyhdr}
\usepackage{graphics}
\usepackage{multicol}
\usepackage{epsfig}
\usepackage{textcomp}
\usepackage{url}

% \usepackage{subfigure}
% \usepackage{subfig}
% \usepackage{wrapfig}


\bibliographystyle{plain}
% \bibliographystyle{sbc}
% \bibliographystyle{abnt-alf}
% \bibliographystyle{abnt-num}

\begin{document}

\sloppy

% \renewcommand{\baselinestretch}{1.24}\normalsize % set the space between lines to 1.24

% set headings
% \pagestyle{fancy}
% \lhead[\fancyplain{}{\footnotesize\thepage}]
%       {\fancyplain{}{\footnotesize\rightmark}}
% \rhead[\fancyplain{}{\footnotesize\leftmark}]
%       {\fancyplain{}{\footnotesize\thepage}}
% 
% \cfoot{}

\lstset{
  language=C,
  basicstyle=\fontsize{8}{8}\selectfont,
  captionpos=t,
  aboveskip=0mm,
  belowskip=0mm,
  abovecaptionskip=0.5mm,
  belowcaptionskip=0.5mm,
%  numbers = left,
  mathescape=true,
  escapechar=@,
  extendedchars=true,
  showstringspaces=false,
%   columns=fixed,
  basewidth=0.515em,
  frame=single,
  framesep=1mm,
  xleftmargin=1mm,
  xrightmargin=1mm,
  framerule=0pt
}

\include{introduction} % Introducao
\bibliography{chd}

\end{document}
