APA (7th ed.) Citation

Fiero, M. O. (1999). Milestones of the 20th century. Grolier.

Chicago Style (17th ed.) Citation

Fiero, Meghan O'Reilly. Milestones of the 20th Century. New York: Grolier, 1999.

MLA (9th ed.) Citation

Fiero, Meghan O'Reilly. Milestones of the 20th Century. Grolier, 1999.

Warning: These citations may not always be 100% accurate.