APA (7th ed.) Citation

Plumb, J. H. (1964). Crisis in the humanities. Penguin Books.

Chicago Style (17th ed.) Citation

Plumb, J. H. Crisis in the Humanities. Baltimore: Penguin Books, 1964.

MLA (8th ed.) Citation

Plumb, J. H. Crisis in the Humanities. Penguin Books, 1964.