Joël Krähemann <jkraehemann@gmail.com>
Daniel Maksymow <daniel.maksymow@tuta.io>

Copyright (C) 2005-2019 Joël Krähemann

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU
Free Documentation License".
