nano /etc/apt/sources.list
deb http://cdn-fastly.deb.debian.org/debian/ jessie main
deb-src http://cdn-fastly.deb.debian.org/debian/ jessie main

deb http://security.debian.org/ jessie/updates main
deb-src http://security.debian.org/ jessie/updates main

deb http://archive.debian.org/debian jessie-backports main
deb-src http://archive.debian.org/debian jessie-backports main

nano /etc/apt/apt.conf
Acquire::Check-Valid-Until "false";

apt-get install htop nano  -t jessie-backports
apt-get update && apt-get upgrade -t jessie-backports -y