Research sources behind the dreadnought comparison

What were the main sources for the dreadnought comparison?

Norman Friedman's books, Brassey's, and Naval Institute transactions with comparative postwar construction reports formed the core source base.

Norman Friedman's books form a major part of the source base for the dreadnought series, alongside copies of Brassey's Naval Annual. Naval Institute transactions provided postwar reports on German and Austro-Hungarian construction and British dreadnought development. Those reports criticize the strengths and weaknesses of several navies. Their comparative approach supports an assessment intended to be balanced rather than partisan.