"national trade union federation of the Soviet Union" . . "associated with various perks" . . . "Trade unions" . "trade unions" . "MGSPS" . . . "the labour unions" . "All-Russian Central Council of Trade Unions" . "Trade unions in the Soviet Union" . . "Trade unions in the Soviet Union" . "Trade Unions" . "All existing trade unions" . "Various trade unions" . "All-Union Central Council of Trade Unions" . . "History of trade unions in the USSR" . "trade union" . "trade unions in the Soviet Union" . "unions" . . "Leningrad Administration of Trade Unions" . "All\u2013Union Central Council of Trade Unions" . "trade Unions" . . . "Soviet era official unions" . . "Soviet Trade Unions" . "Soviet trade union" . "unionized workers" . . "Russian Trade Unions" . . "Soviet trade unions" .