Columbia subject headings:
Motion picture industry--Employees--Labor unions--United States--History.
Motion picture industry--United States--History.
Screen Actors Guild--History.
Harvard subject headings:
Motion picture industry--Employees--Labor unions--United States--History.
Motion picture industry--United States--History
Screen Actors Guild--History.
Princeton subject headings:
Motion picture industry--Employees--Labor unions--United States--History.
Motion picture industry--United States--History.
Screen Actors Guild--History.