APA (7th ed.) Citation

Barber, J. P. (1991). An historical and persistent interest. International affairs, 67(4), 723.

Chicago Style (17th ed.) Citation

Barber, James P. "An Historical and Persistent Interest." International Affairs 67, no. 4 (1991): 723.

MLA (8th ed.) Citation

Barber, James P. "An Historical and Persistent Interest." International Affairs, vol. 67, no. 4, 1991, p. 723.