Columbia subject headings:
Harvard subject headings:
Broadcast journalism--Canada--History--20th century.
Canadian Press--History--20th century.
Journalism--Canada--History--20th century.
News agencies--Canada--History--20th century.
Press--Canada--History--20th century.
Princeton subject headings:
Broadcast journalism--Canada--History--20th century.
Canadian Press--History--20th century.
Journalism--Canada--History--20th century.
News agencies--Canada--History--20th century.
Press--Canada--History--20th century.