source: West Berlin had its own postal administration, separate from West Germany's, which produced its own postage stamps until 1990
target: West Berlin had its own postal administration, separate from West Germany's, which issued its own postage stamps until 1990.
references: West Berlin had its own postal administration, separate from West Germany's, which issued its own postage stamps until 1990. West Berlin had its own postal administration, separate from West Germany which issued its own postage stamps. Until 1990, West Berlin had its own postal system, which used its own postage stamps, separate from West Germany. West Berlin had its own postal administration, separate from West Germany's, which issued its own postage stamps until 1990. West Berlin had its own postal administration, separate from West Germany ’ s, which gave out its own postage stamps until 1990. West Berlin had its own postal administration, from West Germany's, which issued its own postage stamps until 1990. West Berlin had its own postal administration, separate from West Germany's, which issued its own postage stamps until 1990.