Peter Mantel, a student working on his dissertation in history, writes Peter Drucker describing his interest in the persecution of professors of "Betriebswirtschaftslehre" (or persons, who later became professors for "BWL" or management studies) by the National socialists and their followers. Drucker's original handwritten response is written on the email.
Mantel, Peter, 1974- (Mon,) studied this question.