National Film Board of Canada. (1969). Overhead projectuals catalogue 1969. National Film Board of Canada.
Cita Chicago (17th ed.)National Film Board of Canada. Overhead Projectuals Catalogue 1969. Montreal: National Film Board of Canada, 1969.
Cita MLA (8th ed.)National Film Board of Canada. Overhead Projectuals Catalogue 1969. National Film Board of Canada, 1969.
Atenció: Aquestes cites poden no estar 100% correctes.