APA (7th ed.) Citation

Olson, S. (2004). Count down: Six kids vie for glory at the world's toughest math competition. Houghton Mifflin.

Chicago Style (17th ed.) Citation

Olson, Steve. Count Down: Six Kids Vie for Glory at the World's Toughest Math Competition. Boston: Houghton Mifflin, 2004.

MLA (9th ed.) Citation

Olson, Steve. Count Down: Six Kids Vie for Glory at the World's Toughest Math Competition. Houghton Mifflin, 2004.