Cita APA

 Stephenson, H. (2020). Life A2- B1: Student's book.  National geographic learning.

Chicago Style Citation

 Stephenson, Helen. Life A2- B1: Student's Book.  National geographic learning, 2020.

Cita MLA

 Stephenson, Helen. Life A2- B1: Student's Book.  National geographic learning, 2020.

Atenció: Aquestes cites poden no estar 100% correctes.