The variant most frequently quoted (the origins of which seem to be lost to history):
"TVGuide: Yet novelists have written "Star Wars" sequels using the same characters and extending their stories.
George Lucas: Oh, sure. They're done outside my little universe. "Star Wars" has had a lot of different lives that have been worked on by a lot of different people. It works without me."
The Actual Version (extended to aid in understanding the context):
"What would it take for you to do a third trilogy, with episodes VII, VIII and IX?
Each time I do a trilogy it's 10 years out of my life. I'll finish ”Episode III” and I'll be 60. And the next 20 years after that I want to spend doing something other than ”Star Wars.” If at 80 I'm still lively and having a good time and think I can work hard for another 10 years between 80 and 90, I might consider it. But don't count on it. There's nothing written, and it's not like I'm completing something. I'd have to start from scratch. [The idea of episodes VII, VIII, and IX] was more of a media thing than it was me.
Do you know how many fans would be willing to feed you Cream of Wheat and wheel you around in your chair if you did?
I don't think that's going to happen. Time catches up with you.
Yet novelists have written "Star Wars" sequels using the same characters and extending their stories.
Oh, sure. They're done outside of my little universe. ”Star Wars” has had a lot of different lives that have been worked on by a lot of other people. It works without me."
The wording changes are minor . . . "outside my little universe" versus "outside of my little universe", and "different people" versus "other people". However, the addition of contextual evidence locks the concept up a bit more tightly.
The TV Guide quote still isn't a devastator on par with the canon quotes from Starlog #337 or Cinescape. However, not only does it remain another confirmation, but it's a wee bit stronger now.