Halas, J., & Martin-Harris, R. (1978). Audio-visual techniques for industry. United Nations.
Cita Chicago (17th ed.)Halas, John, i Roy Martin-Harris. Audio-visual Techniques for Industry. New York: United Nations, 1978.
Cita MLA (9th ed.)Halas, John, i Roy Martin-Harris. Audio-visual Techniques for Industry. United Nations, 1978.
Atenció: Aquestes cites poden no estar 100% correctes.