http://en.wikipedia.org/wiki/Billiard_ball

http://www.billiard-balls.com/

http://www.ozonebilliards.com/balandbalrac.html

http://www.abcbilliardplus.com/Balls.htm

http://www.cheapshotbilliards.com/pool-balls-billiard-ball-sets.html

http://www.answers.com/topic/billiard-ball-2

http://www.pooldawg.com/category/pool-and-billiard-balls

http://www.89billiardz.com/trbiba.html

http://www.billiardsstore.com/category/tcat/52.cfm

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