As for the astronauts and kosmonauts, you'll find links on
The UFO Skeptic's Page.

Scroll for Oberg's contributions.

I always liked best those people who claimed that the UFOs were in reality human crafts coming from the openings at the poles steered by Nazis who had found a refuge in the hollow earth, a kind of theory unifying the hollow earthers with the Ufologists.

LH, I thought your English was perfect but showed your way of thinking.

Wolfgang