U.S. Department of State. Bureau of Intelligence and Research. "Bulgaria." Pages 61-63 in World Strength of the Communist Party Organization, (23rd annual edition.) Washington: GPO, 1971.
U.S. Department of State. Bureau of Public Affairs. Office of Media Services. "Educational and Cultural Exchange Between Communist and Non-Communist Countries in 1971." (News Release.) December 8, 1972.
Verin, Velko. "Getting Into Print in Bulgaria," East Europe, XVIII, No. 1, January 1969, 22-24.
Women in the People's Republic of Bulgaria. Sofia: Sofia Press, 1971.
World Radio-TV Handbook, 1973. (Ed., J.M. Frost.) Hvidovre: World Radio-TV Handbook, 1973.
"Youth Time" East Europe, XXI, No. 10, October 1972, 23-24.
Section III. Economic
Alton, Thad P. "Economic Structure and Growth in Eastern Europe." In U.S. Congress. 91st, 2d session. Joint Economic Committee. Economic Development in Countries of Eastern Europe. Washington: GPO, 1970.
Costello, Michael. "Bulgaria." Pages 135-157 in Adam Bromke, and Teresa Rakowska-Harmstone (eds.), Communist States in Disarray, 1965-1971. Minneapolis: University of Minnesota Press, 1972.
Dellin, L. A. D. (ed.) Bulgaria: East-Central Europe Under the Communists. New York: Praeger, 1957.