Mulligan, C. B., & Sala-i-Martin, X. (1999). Social security in theory and practice (II): Facts and political theories. National Bureau of Economic Research.
Chicago-Zitierstil (17. Ausg.)Mulligan, Casey B., und Xavier Sala-i-Martin. Social Security in Theory and Practice (II): Facts and Political Theories. Cambridge: National Bureau of Economic Research, 1999.
MLA-Zitierstil (9. Ausg.)Mulligan, Casey B., und Xavier Sala-i-Martin. Social Security in Theory and Practice (II): Facts and Political Theories. National Bureau of Economic Research, 1999.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.