User:SOTO/Forum Archive/The Reference Desk/@comment-65.175.232.112-20131124140519/@comment-1432718-20131125041033
From Tardis Wiki, the free Doctor Who reference
We have articles for Level 2 planet, Level 5 planet and Level 6 planet. I'm not familiar with the story in question, but I think these articles cover pretty much all we know about the different levels.
