Cita APA (7a ed.)

Jackson, S., & Myers, C. (2007). What´s up ? Extra practice 1.

Cita Chicago Style (17a ed.)

Jackson, Sarah, y Cathy Myers. What´s Up ? Extra Practice 1. Pearson Education, 2007.

Cita MLA (8a ed.)

Jackson, Sarah, y Cathy Myers. What´s Up ? Extra Practice 1. 2007.