Cita APA (7th ed.)
(1977). Statistical abstract of the United States 1977. Department of Commerce : National Bureau of Standards.
Cita Chicago (17th ed.)
Statistical Abstract of the United States 1977. Washington, EUA: Department of Commerce : National Bureau of Standards, 1977.
Cita MLA (9th ed.)
Statistical Abstract of the United States 1977. Department of Commerce : National Bureau of Standards, 1977.
Atenció: Aquestes cites poden no estar 100% correctes.