Bibliografia

Principal

• New language leader-pre-intermediate coursebook: Lebeau, I., & Rees, G. 2014 Lebeau, I., & Rees, G. (2014). New language leader-pre-intermediate coursebook. Pearson.
• Macmillan English grammar in context - Intermediate: Vince, M. 2009 Vince, M. (2009). Macmillan English grammar in context - intermediate. Macmillan education.  
• English verbs and tenses: Bourke, K. 2003 Bourke, K. (2003). English verbs and tenses. Oxford University Press.

Secundária

• Oxford advanced learner's dictionary: Hornby, A.S. 2010 Hornby, A.S. (2010). Oxford advanced learner's dictionary. Oxford University Press.