Williamson, E. G., & Cowan, J. L. (1966). The American student's freedom of expression: A research appraisal. University of Minnesota Press.
Dyfyniad Arddull ChicagoWilliamson, Edmund Griffith, and John L. Cowan. The American Student's Freedom of Expression: A Research Appraisal. Minneapolis: University of Minnesota Press, 1966.
Dyfyniad MLAWilliamson, Edmund Griffith, and John L. Cowan. The American Student's Freedom of Expression: A Research Appraisal. University of Minnesota Press, 1966.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.