Copyright for gap-alnuth source package in Xenial

Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: Alnuth
Source: ftp://ftp.gap-system.org/pub/gap/gap4/tar.bz2/packages

Files: *
Copyright: Copyright 2011 Bjoern Assmann, Andreas Distler , Bettina Eick 
License: GPL-2+

Files: debian/*
Copyright: Copyright 2014 Bill Allombert 
License: GPL-2+

License: GPL-2+
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 2 of the license, or
 (at your option) any later version.
 .
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of    
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the     
 GNU General Public License for more details.                      
 .                                                       
 You should have received a copy of the GNU General Public License
 along with this program. If not, see .
 .
 On Debian systems, the full text of the GNU General Public
 License version 2 can be found in the file
 `/usr/share/common-licenses/GPL-2'.