Cita APA (7th ed.)

Key, V. O. (1958). Politics, parties and pressure groups (4th edition.). Crowell.

Cita Chicago (17th ed.)

Key, Valdimer Orlando. Politics, Parties and Pressure Groups. 4th edition. New York: Crowell, 1958.

Cita MLA (9th ed.)

Key, Valdimer Orlando. Politics, Parties and Pressure Groups. 4th edition. Crowell, 1958.