Columbia subject headings:
Agricultural laborers--California--History--20th century.
Agricultural laborers--Labor unions--California--History--20th century.
Agriculture and state--California--History--20th century.
Agriculture--Economic aspects--California--History--20th century.
Harvard subject headings:
Agricultural laborers--California--History--20th century.
Agricultural laborers--Labor unions--California--History--20th century.
Agriculture and state--California--History--20th century.
Agriculture--Economic aspects--California--History--20th century.
Princeton subject headings:
Agricultural laborers--California--History--20th century.
Agricultural laborers--Labor unions--California--History--20th century.
Agriculture and state--California--History--20th century.
Agriculture--Economic aspects--California--History--20th century.