Mulligan, C. B., & Sala-i-Martin, X. (1999). Gerontocracy, retirement, and social security. National Bureau of Economic Research.
芝加哥风格引文Mulligan, Casey B., 与 Xavier Sala-i-Martin. Gerontocracy, Retirement, and Social Security. Cambridge: National Bureau of Economic Research, 1999.
MLA引文Mulligan, Casey B., 与 Xavier Sala-i-Martin. Gerontocracy, Retirement, and Social Security. National Bureau of Economic Research, 1999.
警告：这些引文格式不一定是100％准确.