Olson, S. (2004). Count down: Six kids vie for glory at the world's toughest math competition. Boston: Houghton Mifflin Company.
استشهاد بنمط شيكاغوOlson, Steve. Count Down: Six Kids Vie for Glory At the World's Toughest Math Competition. Boston: Houghton Mifflin Company, 2004.
MLA استشهادOlson, Steve. Count Down: Six Kids Vie for Glory At the World's Toughest Math Competition. Boston: Houghton Mifflin Company, 2004.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.