ebrary, Inc, Salkie, R., Busuttil, P., & Auwera, J. v. d. (2009). Modality in English: Theory and description. Mouton de Gruyter.
芝加哥风格引文ebrary, Inc, Raphael Salkie, Pierre Busuttil, 与 Johan van der Auwera. Modality in English: Theory and Description. Berlin ; New York: Mouton de Gruyter, 2009.
MLA引文ebrary, Inc, et al. Modality in English: Theory and Description. Mouton de Gruyter, 2009.
警告：这些引文格式不一定是100％准确.