APA

Heffington S., Oler A. & Tretler D. (2019). A national security strategy primer. Washington D.C: National Defense University Press.

Chicago

Heffington Steven, Oler Adam and Tretler David. 2019. A national security strategy primer. Washington D.C: National Defense University Press.

Harvard

Heffington S., Oler A. and Tretler D. (2019). A national security strategy primer. Washington D.C: National Defense University Press.

MLA

Heffington Steven, Oler Adam and Tretler David. A national security strategy primer. Washington D.C: National Defense University Press. 2019.