United States. Bureau of the Census. Population Division. (1978). World population, 1977: Recent demographic estimates for the countries and regions of the world. U. S. Government Printing Office.
Chicago-viite (17. p.)United States. Bureau of the Census. Population Division. World Population, 1977: Recent Demographic Estimates for the Countries and Regions of the World. Washington: U. S. Government Printing Office, 1978.
MLA-viite (9. p.)United States. Bureau of the Census. Population Division. World Population, 1977: Recent Demographic Estimates for the Countries and Regions of the World. U. S. Government Printing Office, 1978.
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