Koritarova, Roza. "The Role and the Position of Trade Unions in the System of Social Administration at the Contemporary Stage: A Report." (A report delivered by Roza Koritarova, President of the Central Council of the Trade Unions at the Tenth Plenum of the Central Council of the Bulgarian Trade Unions.) Sofia: Profizdat, 1969.
Kraus, Wolfgang. "Is Bulgaria Closing the Gap?" East Europe, XV, No. 4, April 1966, 2-11.
Larabee, F. Stephen. "Bulgaria's Politics of Conformity," Problems of Communism, XXI, No. 4, February 20, 1972, 42-53.
Lauwerys, Joseph A., and Scanlon, David G. "Education in Cities," The World Year Book of Education, 1970. New York: Harcourt, Brace and World, 1970.
"Liberals Under Fire," East Europe, XXI, No. 5, May 1972, 35.
Morgan, Dan. "Bulgaria Moving Cautiously to Better U.S. Ties," Washington Post, March 29, 1973, A15.
Mossechkov, Nedyalko. "University Library," Bulgaria Today [Sofia], X, No. 7, July 1961, 25-26.
Newman, Bernard. Bulgarian Background. London: Robert Hale, 1961.
Olson, Kenneth E. The History Makers. Baton Rouge: Louisiana State University Press, 1966.
Oren, Nissan. Revolution Administered: Agrarianism and Communism in Bulgaria. Baltimore: Johns Hopkins University Press, 1973.