Did You Know That Women Are Still Paid Less Than Men? - https://www.whitehouse.gov/equal-pay/career

As Obama Spotlights Gender Gap in Wages, His Own Payroll Draws Scrutiny - http://www.nytimes.com/2014/04/08/us/politics/as-obama-spotlights-gender-gap-in-wages-his-own-payroll-draws-scrutiny.html

The ‘Equal Pay Day’ factoid that women make 78 cents for every dollar earned by men - https://www.washingtonpost.com/blogs/fact-checker/wp/2015/04/02/the-equal-pay-day-factoid-that-women-make-78-cents-for-every-dollar-earned-by-men/ 

Explaining the Gender Wage Gap - https://www.americanprogress.org/issues/economy/report/2014/05/19/90039/explaining-the-gender-wage-gap/