Columbia subject headings:
Harvard subject headings:
Cleaning personnel--Labor unions--Germany.
Cleaning personnel--Labor unions--United States.
Industriegewerkschaft Bauen-Agrar-Umwelt.
Labor unions--Germany
Labor unions--Organizing--Germany.
Labor unions--Organizing--United States
Labor unions--United States
Service Employees International Union.
Princeton subject headings:
Cleaning personnel--Labor unions--Germany.
Cleaning personnel--Labor unions--United States.
Industriegewerkschaft Bauen-Agrar-Umwelt.
Labor unions--Germany.
Labor unions--Organizing--Germany.
Labor unions--Organizing--United States.
Labor unions--United States.
Service Employees International Union.