APA (7th ed.) Citation

Bolinger, D. L. M. (1957). Interrogative structures of American English: The direct question. University of Alabama Press.

Chicago Style (17th ed.) Citation

Bolinger, Dwight Le Merton. Interrogative Structures of American English: The Direct Question. Alabama: University of Alabama Press, 1957.

MLA (8th ed.) Citation

Bolinger, Dwight Le Merton. Interrogative Structures of American English: The Direct Question. University of Alabama Press, 1957.