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