Cita APA (7th ed.)
Dean, M. Opportunities: Intermediate : Language Powerbook. Pearson.
Cita Chicago (17th ed.)
Dean, Michael. Opportunities: Intermediate : Language Powerbook. Harlow, Inglaterra: Pearson.
Cita MLA (9th ed.)
Dean, Michael. Opportunities: Intermediate : Language Powerbook. Pearson.
Atenció: Aquestes cites poden no estar 100% correctes.