Bell, S. (1940). Productivity, wages, and national income. Brookings Institution.
Chicago Style (17. basım) AtıfBell, Spurgeon. Productivity, Wages, and National Income. Washington, D.C: Brookings Institution, 1940.
MLA (9th ed.) AtıfBell, Spurgeon. Productivity, Wages, and National Income. Brookings Institution, 1940.
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