Cita APA

Frazier, L., & Mills, R. (2009). Northstar 2: Listening and speaking. (3. ed.). New York: Pearson education.

Citación estilo Chicago

Frazier, Laurie, y Robin Mills. Northstar 2: Listening and Speaking. 3. ed. New York: Pearson education, 2009.

Cita MLA

Frazier, Laurie, y Robin Mills. Northstar 2: Listening and Speaking. 3. ed. New York: Pearson education, 2009.