Source: US. Bureau of the Census
Release: Annual Services Survey
For further information, please refer to the US Census Bureau's Annual Services release, online at http://www.census.gov/services/.
US. Bureau of the Census, Sources of Revenue: Transportation Infrastructure Engineering Projects for Engineering Services, All Establishments, Employer Firms [REVTIEEF54133ALLEST], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/REVTIEEF54133ALLEST, September 26, 2016.