So I'm watching Ancient Aliens and it was good for a laugh until...

...One of their interviewees attributed the following quote to Nazi rocketry researcher Hermann Oberth: "We have been helped by people from other worlds."

Something about that stuck out, so I decided to look it up. Don't get me wrong, I'm well aware that the show takes a lot of liberties with context and translations, and is basically one long Reduction to the Absurd, but an outright lie?

I can't find a source for that quote at all, and it's only popping up on UFO websites, uncited.