United States. Bureau of the Census. 1977 census of construction industries: Industry series, bridge, tunnel, and elevated highway construction contractors, SIC code 1622.
Chicago Style (17th ed.) CitationUnited States. Bureau of the Census. 1977 Census of Construction Industries: Industry Series, Bridge, Tunnel, and Elevated Highway Construction Contractors, SIC Code 1622.
MLA (9th ed.) CitationUnited States. Bureau of the Census. 1977 Census of Construction Industries: Industry Series, Bridge, Tunnel, and Elevated Highway Construction Contractors, SIC Code 1622.
Warning: These citations may not always be 100% accurate.