APA (7th ed.) Citation

Hopper, P. J., & Traugott, E. C. (1993). Grammaticalization. University Press.

Chicago Style (17th ed.) Citation

Hopper, Paul J., and Elizabeth Closs Traugott. Grammaticalization. Cambridge: University Press, 1993.

MLA (9th ed.) Citation

Hopper, Paul J., and Elizabeth Closs Traugott. Grammaticalization. University Press, 1993.