. . James R. Mock und Cedric Larson, Words That Won the War: The Story of the Committee on Public Information, Princeton (Princeton University Press) 1939, S.214; Mark Sullivan, Our Times, Band V, New York (Scribners) 1933, S.167,169; Motion Picture News, 23. März 1918, S.1769; Lewis Jacobs, The Rise of American Film, New York (Harcourt, Brace) 1939, S.258.