Between 1960 and 1990, nearly 12,000 African students graduated from Bulgaria. The exact number is unknown, according to a research by Prof. Svetla Koleva, a sociologist at the Bulgarian Academy of Sciences. The lost connection with these people means lost opportunities for Bulgaria, because under various intergovernmental agreements before 1989, this country invested in the training of specialists from Africa. During the Cold War, education was an instrument of influence for the Bulgarian state, but today this is an untapped opportunity for Bulgarian society to keep contact with the African continent, Koleva said. There have also been integration problems reported when it came to African specialists who stayed in Bulgaria to this day.