deb-src http://ftp.de.debian.org./debian bullseye main contrib non-free deb-src http://ftp.de.debian.org./debian bullseye-updates main contrib non-free deb-src http://ftp.de.debian.org./debian bullseye-proposed-updates main contrib non-free deb-src http://security.debian.org./debian-security bullseye-security main contrib non-free deb-src http://ftp.de.debian.org./debian bullseye-backports main contrib non-free