Cita APA (7a ed.)

Herrera, M., & Pinkley, D. (2005). Backpack 3: Workbook.

Cita Chicago Style (17a ed.)

Herrera, Mario, y Diane Pinkley. Backpack 3: Workbook. Longman, 2005.

Cita MLA (8a ed.)

Herrera, Mario, y Diane Pinkley. Backpack 3: Workbook. 2005.