Cita APA (7th ed.)

Labov, W. (1994). Principles of linguistic change. Blackwell.

Cita Chicago (17th ed.)

Labov, William. Principles of Linguistic Change. Oxford, UK, Cambridge [Mass.]: Blackwell, 1994.

Cita MLA (9th ed.)

Labov, William. Principles of Linguistic Change. Blackwell, 1994.