If Humans Were Built to Last,” S. Jay Olshansky, Bruce Carnes and Robert Butler, Fast Forward

A Potential Decline in Life Expectancy in the United States in the 21st Century,” By S. Jay Olshansky and others, New England Journal of Medicine

S. Jay Olshansky website

Population Reference Bureau, data and reports

An Aging Nation,” 2017 U.S. Census Bureau report

Centers for Disease Control and Prevention life expectancy data