\documentclass[oneside]{article}

\usepackage{graphicx}
\usepackage{pstricks}

\setlength{\oddsidemargin}{-1.27cm}
\setlength{\textwidth}{18.46cm}
\setlength{\topmargin}{-1.27cm}
\setlength{\headheight}{0cm}
\setlength{\headsep}{0cm}
\setlength{\textheight}{25.89cm}

\begin{document}

\pagestyle{empty}

\begin{center}
\mbox{}\vfill
\includegraphics[width=20cm,keepaspectratio,angle=90]{BaseFramework}
\vfill\mbox{}

\newpage

\mbox{}\vfill
\includegraphics[height=18cm,keepaspectratio,angle=90]{ExtendedFramework}
\vfill\mbox{}

\newpage

\mbox{}\vfill
	\includegraphics[width=20cm,keepaspectratio,angle=90]{MultipleSchemes}
\vfill\mbox{}
\end{center}

\end{document}