Handbook of Methods Establishment Survey - (http://www.bls.gov/opub/hom/pdf/homch2.pdf)
Frequently Asked Questions - (http://stats.bls.gov:80/cps/cps_faq.htm)
The series comes from the 'Current Employment Statistics (Establishment Survey)'
The source code is: CES0700000001
Source: US. Bureau of Labor Statistics
Release: Employment Situation
US. Bureau of Labor Statistics, All Employees: Service-Providing Industries [SRVPRD], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/SRVPRD/, July 6, 2015.