Cita APA (7a ed.)

Emerson, T. I. (1971). The system of freedom of expression. Vintage Books.

Cita Chicago Style (17a ed.)

Emerson, Thomas Irwin. The System of Freedom of Expression. New York: Vintage Books, 1971.

Cita MLA (9a ed.)

Emerson, Thomas Irwin. The System of Freedom of Expression. Vintage Books, 1971.