As my history professor said for a while during the 60s all the way to the 90s any book that had a swastika on it would sell. Your options here are limitless, I haven’t done much reading on the third Reich leaders myself but I know a few. Rommel would often write his own stuff and that’s a pretty juicy primary source. If you want to see the effects these leaders had on occupied countries Mila 18 is a great fictional (but historically accurate) read about the ghettos in Poland. And then there’s the big one you know Mien Kampf which I must warn you is the rambling of a mad man but is interesting none the less. I’m sure someone else will have much better suggestions than me, but I can promise you, ya got a lot of options in this area.