The problem - as with so many Yogi quotes - is finding the quote. As Yogi himself allegedly said, "I never really said everything I said." If anyone has better, I'll add it below.
4 September 1973, New York Post, "Time Running Out on Mets," , pg. 64, col. 1:
Yeah, it's running out, but you're still not out of it until it's automatic," Yogi Berra revealed late yesterday afternoon.
30 June 1974, New York Times, "A 'Character' Named Berra" by Red Smith, pg. 191:
He is not yet ready to admit that this year's Mets can't repeat. "You're not out of it," he insisted recently, "until you're out of it."
6 September 1977, Washington Post, pg. D2:
"It's not over," Pirate manager Chuck Tanner insisted after the split. "Things can turn around in a week in baseball. It's over when the numbers say it's over."
23 August 1979, New York Times, pg. B11:
"It's never over until it's over," Yogi Berra once said.

