Economic intefration and industrial specialization among the member countries of the mutual economic assistance / United nations. United Nations. Department of Economic and Social Affairs. United Nations Population forecasting. HB848.U54 no.31 330.9 UNE United Nations. Document ST/SOA/Ser. A/31. New York : United nations, 1966. 1966. 1966 Text v. ; eng Future population estimates by sex and age ; report no. 4 Population Studies / United Nations. Dept. of Economic and Social Affairs ; no. 31 Population studies (New York, N.Y.) ; no. 31