Standard industrial classification manual :
1977 supplement / U.S. Department of Commerce, Office of Federal Statistical Policy and Standards.

APA Citation

United States. Office of Federal Statistical Policy and Standards., United States. Technical Committee on Industrial Classification. (1978). Standard industrial classification manual: 1977 supplement / U.S. Department of Commerce, Office of Federal Statistical Policy and Standards. Washington: The Office : for sale by the Supt. of Docs., U.S. Govt. Print. Off..

MLA Citation

United States. Office of Federal Statistical Policy and Standards, and United States. Technical Committee on Industrial Classification. Standard Industrial Classification Manual: 1977 Supplement / U.S. Department of Commerce, Office of Federal Statistical Policy And Standards. Washington: The Office : for sale by the Supt. of Docs., U.S. Govt. Print. Off., 1978.