How to install alsa-base and pulseaudio?

Question

I was having a sound issue where sound settings show "dummy output" meaning it wasn't reading my audio card.

I followed this instructions here, got to the "alternate" method, ran "sudo apt-get remove --purge alsa-base pulseaudio", but "sudo apt-get install alsa-base pulseaudio" shows me this:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package pulseaudio is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

Package alsa-base is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'alsa-base' has no installation candidate
E: Package 'pulseaudio' has no installation candidate

No I don't even have a sound icon. How can I install these two packages?

Solution

Adding the following line to my sources list allowed me to install these packages:

deb http://cz.archive.ubuntu.com/ubuntu raring main 

A bigger list of mirrors can be found here on packages.ubuntu.com

The audio symbol returned and settings are there, but my "dummy output" problem persists.