APA (7th ed.) Citation

Twaddell, W. F. (1963). The English verb auxiliaries (2d ed. rev.). Brown University Press.

Chicago Style (17th ed.) Citation

Twaddell, W. F. The English Verb Auxiliaries. 2d ed. rev. Providence: Brown University Press, 1963.

MLA (9th ed.) Citation

Twaddell, W. F. The English Verb Auxiliaries. 2d ed. rev. Brown University Press, 1963.