Triumph of the Will is available, and I don't think you can get more "primary source" than that, while keeping in mind it is propaganda, and doesn't mean to hide that fact at all (because it was, in fact, made to celebrate both Germany and the NSDAP).
Oh, and the first few minutes is really just footage from out of an airplane window; keep in mind that not many people had flown yet, so it would have been pretty cool in 1935. Otherwise, most of it is speeches.
Not a book, and I haven't watched it yet because it's over 6 hours long, but this should be right up your alley. https://odysee.com/@CyberNews:c/The-Greatest-Story-Never-Told:7
Triumph of the Will is available, and I don't think you can get more "primary source" than that, while keeping in mind it is propaganda, and doesn't mean to hide that fact at all (because it was, in fact, made to celebrate both Germany and the NSDAP).
Oh, and the first few minutes is really just footage from out of an airplane window; keep in mind that not many people had flown yet, so it would have been pretty cool in 1935. Otherwise, most of it is speeches.
It's worth seeing just for historical interest.
https://www.dailymotion.com/video/x6uajey