\documentclass[a4paper,12pt,oneside]{article}

\setlength{\parindent}{0cm}
\setlength{\textwidth}{12cm}
\setlength{\textheight}{16cm}
\setlength{\hoffset}{-0.3cm}
\setlength{\voffset}{1.0cm}

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\renewcommand{\headheight}{15pt}
\renewcommand{\headrulewidth}{0pt}
\setlength{\parindent}{0pt}
\oddsidemargin=2.35cm %define oddsidemargin

\begin{document}

%Heading
\begin{center}
\textbf{Presentation Title} \bigskip\\

First Name$^a$, \underline{Presenters Name}$^a$, Second Name$^a$*, Third Name$^b$* \bigskip\\ % * is contact person(s)

$^a$ First Institution/Company, Street, Zip, Town, Country \\
$^b$ Second Institution/Company, Street, Zip, Town, Country \\
\end{center}

%Main Text
Maximum one page of abstract with text, citations$^1$, formulas and figures...\vspace{12pt}\\
The current format will be reduced to 70\% in the final book of abstracts which features four abstracts per page. Fontsize 12 shrinks to fontsize 8, and the width and height currently 16 x 12 cm shrinks to 11.4 x 8.4 cm (see attachments).\vspace{12pt}\\
Lorem ipsum dolor sit amet, consetetur sadipscing elitr,  sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr,  sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr,  sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.\\

%References
\bigskip
\begin{tabular}{rl}
{[1]} & F. Autor, S. Author, \emph{Journal Abbr.}, \textbf{2000}, \emph{4}, 412. \\
{[2]} & ... \\
{[3]} & ... \\
\end{tabular}

\end{document}
