APA

Head A., Knight K. & London S. (2007). English. London: Letts Educational.

Chicago

Head Alison, Knight Katy and London Sophie. 2007. English. London: Letts Educational.

Harvard

Head A., Knight K. and London S. (2007). English. London: Letts Educational.

MLA

Head Alison, Knight Katy and London Sophie. English. London: Letts Educational. 2007.