(1940). Audio-visual aids to instruction / by Harry C. McKown...and Alvin B. Roberts.
Cita Chicago (17th ed.)Audio-visual Aids to Instruction / by Harry C. McKown...and Alvin B. Roberts. 1940.
Cita MLA (9th ed.)Audio-visual Aids to Instruction / by Harry C. McKown...and Alvin B. Roberts. 1940.
Atenció: Aquestes cites poden no estar 100% correctes.