Economic concentration and the monopoly problem / Edward Sagendorph Mason Mason, Edward Sagendorph, 1899- Big business United States. Trusts, Industrial United States. HD2785 .M36 338.82 MAE Cambridge : Harvard University Press, 1957. 1957. 1957 Text xvi, 411 p. : eng Harvard economic studies, v. 100 United States. United States.