APA
Schmergel G. (., . (1991). US foreign policy in the 1990s. London: Macmillan.
Chicago
Schmergel Greg (ed), . 1991. US foreign policy in the 1990s. London: Macmillan.
Harvard
Schmergel G. (., . (1991). US foreign policy in the 1990s. London: Macmillan.
MLA
Schmergel Greg (ed), . US foreign policy in the 1990s. London: Macmillan. 1991.