Cita APA (7th ed.)

Stephenson, H. (2014). Life: Beginner. Workbook (1a. ed.). National Geographic Learning.

Cita Chicago (17th ed.)

Stephenson, Helen. Life: Beginner. Workbook. 1a. ed. Hampshire: National Geographic Learning, 2014.

Cita MLA (9th ed.)

Stephenson, Helen. Life: Beginner. Workbook. 1a. ed. National Geographic Learning, 2014.