Also, TT, you might be interested in the following:
https://www.space.com/sciencefiction...on_000601.html Robert A. Heinlein A Biographical Sketch
And, despite some serious factual errors, I think you'd find Leon Stover's Robert A. Heinlein both informative and thought-provoking. As noted elsewhere, it was the first major book to come out on RAH with a positive view. It is also quite entertaining to read.