APA (7th ed.) Citation

Geddes, J. (2004). A Big Step Toward Missile Defence. Maclean's, 117(33), 21.

Chicago Style (17th ed.) Citation

Geddes, John. "A Big Step Toward Missile Defence." Maclean's 117, no. 33 (2004): 21.

MLA (9th ed.) Citation

Geddes, John. "A Big Step Toward Missile Defence." Maclean's, vol. 117, no. 33, 2004, p. 21.