Cita APA (7th ed.)
Penny, R. Variation and Change in Spanish. Cambridge University.
Cita Chicago (17th ed.)
Penny, Ralph. Variation and Change in Spanish. Cambridge, Inglaterra: Cambridge University.
Cita MLA (9th ed.)
Penny, Ralph. Variation and Change in Spanish. Cambridge University.
Atenció: Aquestes cites poden no estar 100% correctes.