(1981). Demographic estimates for countries with a population of 10 million or more, 1981. Washington: U.S. Government Printing Office.
Παραπομπή Chicago StyleDemographic Estimates for Countries With a Population of 10 Million or More, 1981. Washington: U.S. Government Printing Office, 1981.
Παραπομπή MLADemographic Estimates for Countries With a Population of 10 Million or More, 1981. Washington: U.S. Government Printing Office, 1981.
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