APA

National Industrial Conference Board, . (1929). A picture of world economic conditions in the summer of 1929. New York: National Industrial Conference Board.

Chicago

National Industrial Conference Board, . 1929. A picture of world economic conditions in the summer of 1929. New York: National Industrial Conference Board.

Harvard

National Industrial Conference Board, . (1929). A picture of world economic conditions in the summer of 1929. New York: National Industrial Conference Board.

MLA

National Industrial Conference Board, . A picture of world economic conditions in the summer of 1929. New York: National Industrial Conference Board. 1929.