I can not install gnome shell

[Hamed Sepehr]

Hi, I have Linux Mint 14.1 and I want to install gnome shell on it but I can't. In Linux Mint 13 I have easily installed gnome shell by typing this address in my browser: apt.ubuntu.com/p/gnome
But in Linux Mint 14.1 when I wanted to install gnome shell by typing that address I received this error: Can not install 'gnome' (E: Unable to correct problem, you have held broken packagesc)
I have seen this topic but I couldn't understand what I should do, exactly. viewtopic.php?f=208&t=117580
Now, how can I install gnome shell?
(sorry for bad English )

[Orbmiser]

Did you look in synapse or software manager? It's in there.
.

[Hamed Sepehr]

I have these packages in software manager. Is it ok to install all of them to have a complete gnome shell desktop?