This text was written in 1970 by Marshall McLuhan, together with Barrington Nevitt, for the anthology Peter Drucker: Contributions to Business Enterprise (eds. Tony H. Bonaparte and John E. Flaherty, New York University Press, 1970, pp. 35-55). The first two paragraphs of the text explicitly deal with the cultural influence which Drucker's hometown of Vienna had on his world view. 

Think of any management idea that is fashionable today and the chances are that Peter Drucker was writing about it before you were born. He has to be at the front of any list of management thinkers, the guru of gurus, as he has been called.