APA-referens (7:e uppl.)

Palmer, F. R. (1990). Modality and the English modals. Longman.

Chicago-referens (17:e uppl.)

Palmer, Frank Robert. Modality and the English Modals. London: Longman, 1990.

MLA-referens (9:e uppl.)

Palmer, Frank Robert. Modality and the English Modals. Longman, 1990.