Hill, F. E., & Williams, W. (1941). Radio's listening groups: The United States and Great Britain. Columbia University Press.
Cita Chicago (17th ed.)Hill, Frank Ernest, i W.E Williams. Radio's Listening Groups: The United States and Great Britain. New York: Columbia University Press, 1941.
Cita MLA (8th ed.)Hill, Frank Ernest, i W.E Williams. Radio's Listening Groups: The United States and Great Britain. Columbia University Press, 1941.
Atenció: Aquestes cites poden no estar 100% correctes.