\thispagestyle{empty} \null\vfill \begin{adjustwidth}{3em}{3em} This book was typeset using the \LaTeX{} document preparation system, which uses Donald E.~Knuth’s \TeX{} typesetting engine. \null \noindent Because no major editing was done to the text, some of the pages may contain widow/orphan lines. \end{adjustwidth} \vfill{} \cleartoend