If you try to install one of them with "apt-get install", you'll see an "Unable to locate package " message.
To add the standard Debian repositories, execute this command:
nano /etc/apt/sources.list
Add this line to the end of the file,
as shown below:
deb http://ftp.us.debian.org/debian wheezy main
Save the file with Ctrl+X, Y, Enter.
Then execute this command:
apt-get update