Signature in preface
\documentclass{article}
\def\sig#1{\vbox{\hsize=5.5cm
\kern2cm\hrule\kern1ex
\hbox to \hsize{\strut\hfil #1 \hfil}}}
\newcommand\signatures[4]{%
\hbox to \hsize{\hfil #1, \today\hfil}
\hbox to \hsize{\quad\sig{#2}\hfil\hfil\sig{#3}\quad}
\hbox to \hsize{\hfil\sig{#4}\hfil}}
\begin{document}
\signatures{St. Anford}{John Doe}{Jane Doe}{James Doe}
\end{document}
Each signature line is 5.5cm
long and you might want to change this in the definition of \sig
. Likewise, each signature line provides 2cm
of vertical space for the actual signature. One \quad
of space is left to the margins - you could use here anything like \hskip1cm
as well.
One possible solution would be to use a tabular
environment (change the lengths according to your needs):
\documentclass[10pt,b5paper,twoside]{report}
\usepackage[lmargin=25mm,rmargin=25mm,tmargin=27mm,bmargin=30mm]{geometry}
\usepackage{array}
\newcommand\Signature[4]{\par\bigskip
\setlength\tabcolsep{0pt}
\begin{tabular}{@{\hspace{.05\textwidth}}>{\centering\arraybackslash}p{.4\textwidth}
@{\hspace*{.1\textwidth}}>{\centering\arraybackslash}p{.4\textwidth}@{\hspace{.05\textwidth}}}
\multicolumn{2}{c}{#1, \today} \\[10ex]
\rule{.4\textwidth}{0.4pt} & \rule{.4\textwidth}{0.4pt} \\
#2 & #3 \\[10ex]
\multicolumn{2}{c}{\rule{.4\textwidth}{0.4pt}} \\
\multicolumn{2}{c}{#4}
\end{tabular}
\par
}
\begin{document}
\Signature{G\"ottingen}{David Hilbert}{Emmy Noether}{Hermann Minkowski}
\end{document}