Butt, J., & Benjamin, C. (1994). A new reference grammar of modern Spanish / John Butt, Carmen Benjamin (2nd ed.). Arnold.
Chicago Style (17th ed.) CitationButt, John, and Carmen Benjamin. A New Reference Grammar of Modern Spanish / John Butt, Carmen Benjamin. 2nd ed. London: Arnold, 1994.
MLA (9th ed.) CitationButt, John, and Carmen Benjamin. A New Reference Grammar of Modern Spanish / John Butt, Carmen Benjamin. 2nd ed. Arnold, 1994.
Warning: These citations may not always be 100% accurate.