Merdinger, P., & Barton, L. Northstar: Listening and speaking (2a ed.).
Cita Chicago (17th ed.)Merdinger, Polly, i Laurie Barton. Northstar: Listening and Speaking. 2a ed.
Cita MLA (8th ed.)Merdinger, Polly, i Laurie Barton. Northstar: Listening and Speaking. 2a ed.
Atenció: Aquestes cites poden no estar 100% correctes.