A memorandum on cooperation was signed Friday in Berlin by the German service dealing with the Stasi archives and the Bulgarian commission on secret police files. The document enables exchange information and expertise. It will also facilitate research into the connections between the former secret services of Bulgaria and what used to be East Germany. The Stasi archives from the 1969-80 period hold 3,800 reports from the Bulgarian secret services. Some of the reports are on political matters and concern Bulgaria`s neighbours or German organizations in Bulgaria. The German secret service, on their part, has sent 1,500 reports to the Bulgarian State Security. The delegation of the Bulgarian commission could not obtain information on files about Bulgarian citizens in the Stasi archives. Under the effective German legislation, such information may be disclosed only if the person named in the document requires access to his or her file. The two commissions are preparing a scientific conference on the influence of the communist secret services in the transitional societies. The forum will be held early next year in Bulgaria.