1. United States Census Bureau Reports ‘Delayer Boom’ as More Educated Women Have Children Later 2011 http://www.census.gov/newsroom/releases/ar-chives/fertility/cb11-83.html
2. Centers for Disease Control Assisted Reproductive Technology (ART): What Is Assisted Reproductive Technology? http://www.cdc.gov/art/
3. Childlessness Up among All Women: Down among Women with Advanced Degrees;Livingston;Pew Research Center,2010
4. Voluntary Sterilization Act 1974
5. Sterilization of Young, Competent, and Childless Adults;Benn;British Medical Journal,2005