Conference on research in income and wealth : Vol. 12 : Studeis in income and wealth / National Bureau of Economic Research National Bureau of Economic Research. Economics HC106.3 .C714 330 19 COS Includes index. With supplements. Issued by: the Conference on Research in National Income and Wealth, 1937-1942; the Conference on Research in Income and Wealth, 1943- Vols. 1 (1937)-25 (1961). New York : National Bureau of Economic Research, 1950. 1950. 1937 Text Collection v. : eng