American Alpine Institute - Climbing Blog: Do I need Climbing Chalk...?
How to Use Climbing Chalk Balls? – Chalk Rebels
Cannon Sports White Loose Chalk with Powder Ball Sock, Magnesium Carbonate for Climbing, Weightlifting & Gymnastics 3lb - Walmart.com
The Chalk Ball – Primo Chalk
Amazon.com: TITGGI 1 lb Gym Chalk Bucket - Includes Chalk Powder and A Chalk Ball - Multi-Purpose Hand Chalk for Rock Climbing Chalk, Gym Chalk, Weight Lifting Chalk and More : Sports