United States. Technical Committee on Industrial Classification & United States. Bureau of the Budget. Office of Statistical Standards. (1957). Standard industrial classification manual. Executive Office of the President, Bureau of the Budget.
Cita Chicago (17th ed.)United States. Technical Committee on Industrial Classification i United States. Bureau of the Budget. Office of Statistical Standards. Standard Industrial Classification Manual. Washington, D.C.: Executive Office of the President, Bureau of the Budget, 1957.
Cita MLA (9th ed.)United States. Technical Committee on Industrial Classification i United States. Bureau of the Budget. Office of Statistical Standards. Standard Industrial Classification Manual. Executive Office of the President, Bureau of the Budget, 1957.