Attached is a 1940 magazine article reporting on the Nazi march through Poland, Norway, Holland, Belgium, and France by military historian and biographer Fairfax Downey (1894 - 1990):
"Air superiority and improved weapons. The fast, hard-hitting motorized column and the stealthy, treacherous Fifth Columns. First-rate tactic, long-planned strategy, and fine staff work. All these add up to the answer, given by the Nazis themselves. A stream of published German military documents has been flowing into our War Department where they have been translated...On these documents are based the following battle pieces."
Click here to read an article about French confidence in the Maginot Line.
More primary source articles about W.W. II France can be read here...
From Amazon: A Copy of the German Army
M40 Feldgrau Blouse