Erdmann, P. (1990). Discourse and grammar: Focussing and defocussing in English. M. Niemeyer.
Lua i Stíl Chicago (17ú heag.)Erdmann, Peter. Discourse and Grammar: Focussing and Defocussing in English. Tübingen: M. Niemeyer, 1990.
Lua MLA (9ú heag.)Erdmann, Peter. Discourse and Grammar: Focussing and Defocussing in English. M. Niemeyer, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.