Book recommendation; "Hitler's flying saucers": Nazi-UFO proof:

Hitler's Flying Saucers: A Guide to German Flying Discs of the Second World War

Stevens turns every stone in his investigation, and provides a very detailed review of the German flying saucer projects during ww2, - from jet-powered 'suction saucers' to potential field propultion saucers.
If you are new to the topic and want a thorough introduction, this is the best place to start.



An amateur video in three parts based on Stevens's book can be watched here;