A long time ago (early seventies) they were being reprinted here in the states (I believe PR originated in Germany). Forrest J Akerman coined the phrase Sci-Fi to describe the series.
I read the 1st several (10)books. Very light reading and entertaining. Stopped because I am a stickler for reading things in order and couldn't find the next book.
Galaxy is a bit like those of the EE 'Doc' Smith space operas (as far as ships, tech, space battles go) from the thirties.
I believe there was a pretty horrid movie made from it also.