Evans, D. L., & Cooper, K. B. B. An Aging World: 2001 /U.S. Department of Commerce. Economics and Statistics Asministration. Government Printing Office.
Chicago-viite (17. p.)Evans, Donald L., ja Kathleen B Barron Cooper. An Aging World: 2001 /U.S. Department of Commerce. Economics and Statistics Asministration. Washington, D.C: Government Printing Office.
MLA-viite (9. p.)Evans, Donald L., ja Kathleen B Barron Cooper. An Aging World: 2001 /U.S. Department of Commerce. Economics and Statistics Asministration. Government Printing Office.
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