The Rocket and the Reich, 1995 book
Von Braun, Dreamer of Space, Engineer of War, 2007 book
Weimar Culture and Futuristic Technology: The Rocketry and Spaceflight Fad in Germany, 1923-1933, in Technology and Culture, 1990
Michael J. Neufeld, National Air and Space Museum, Smithsonian
I borrowed both books from the library, intending to learn more about how Wernher von Braun was influenced by Hermann Oberth's books. I read both books through to the end; a lot of events and statistics and dates that would bore most readers, fascinating to an engineer, the 1995 book more recently. What about Oberth? The 100 page Die Rakete zu den Planetenräumen thesis has recently been translated to English, and the 300 page expansion, Wege zur Raumschiffahrt is available in print in a 1972 English translation by NASA, Ways to spaceflight, TT F-622, and online (a page at a time here.
I also looked at The Nazi Rocketeers and Werner Von Braun by Dennis Piszkiewicz. On page 23 of the latter, Piszkiewicz says WvB "came across an advertisement in an astronomy magazine for a book he remembered as Road to the Planets (this was probably Wege zur Raumschiffahrt ... ". Neufeld says Die Rakete zu den Planetenräumen. Both authors mention the math in "the" Oberth book inspiring the teenage von Braun to buckle down and study math and physics. If the language is similar in the two Oberth versions, I'll look at "Wege ..." in English and judge its inspiration potential.
Perhaps it was actually the popularizations by Willy Ley and Max Valier that inspired WvB, and the Oberth citation (by WvB) an adult rewriting and embellishment of a more childish process. I was inspired by science fiction writers like Heinlein, and encouraged to learn calculus by the differential equations in an advanced transistor book I bought ($$$) as a teenager. "Too hard" can be a powerful motivator.
Neufeld's 1990 Weimar ... article is perhaps the most enlightening of his three writings listed here. This does not focus on von Braun, but it does describe how rockets captured popular imagination in 1927 to 1929, then faded into the background, while serious and capable rocketeers like von Braun were drawn into the secret weapon program funded by German Army Ordnance.
The V2 program seriously damaged the German war effort. Neufeld mentions the tens of thousands of aircraft, tanks, and other more effective war machines that could have been manufactured with the same resources. Those resources included concentration camp prisoners worked to death at Mittlewerk. Without diminishing the V2 team's culpability, it is probable that the same underground factory and prisoners would have been expended on other weapons projects. Those 3000+ V2s used 12,000 tonnes of highly enriched alcohol; I estimate that alcohol was brewed from 200,000 tonnes of food, which could have fed millions for months. I do not know how big a role starvation played in the Nazi defeat, but I presume hunger clouded judgment, making German fighters ineffective and German factory workers slow and incompetent.
After World War 2, the US and the USSR spent trillions developing ballistic missile technology based on German achievements. Hitler's two worst enemies came close to wiping each other out with nuclear warheads, the optimum weapon for rocket delivery. So in a way, Hitler's superweapon failure was almost a success.