Debian 7 DOWNLOAD
http://cdimage.debian.org/debian-cd/current/multi-arch/iso-dvd/
Debian 7 Sources：
deb http://ftp.de.debian.org/debian/ squeeze main contrib non-free
deb-src http://ftp.de.debian.org/debian/ squeeze main contrib non-free
deb http://security.debian.org/ squeeze/updates main contrib non-free
deb-src http://security.debian.org/ squeeze/updates main contrib non-free
# squeeze-updates, previously known as 'volatile'
deb http://ftp.de.debian.org/debian/ squeeze-updates main contrib non-free
deb-src http://ftp.de.debian.org/debian/ squeeze-updates main contrib non-free
http://cdimage.debian.org/debian-cd/current/multi-arch/
http://ftp.de.debian.org/debian/dists/Debian7.1/contrib/source/