Cita APA (7th ed.)

U.S. Bureau of the Census. (1981). Demographic estimates for countries with a population of 10 million or more: 1981. U.S. Government Printing Office.

Cita Chicago (17th ed.)

U.S. Bureau of the Census. Demographic Estimates for Countries with a Population of 10 Million or More: 1981. Washington, D.C: U.S. Government Printing Office, 1981.

Cita MLA (9th ed.)

U.S. Bureau of the Census. Demographic Estimates for Countries with a Population of 10 Million or More: 1981. U.S. Government Printing Office, 1981.