APA (7th ed.) Citation

Engel, C., & Rogers, J. H. (1994). How wide is the border?

Chicago Style (17th ed.) Citation

Engel, Charles, and John H. Rogers. How Wide Is the Border? Cambridge, Mass, 1994.

MLA (9th ed.) Citation

Engel, Charles, and John H. Rogers. How Wide Is the Border? 1994.