1. Jake Kolipano- Template design, consultation.

2. Polarnet. (Hockey rink picture)

3. Physics for scientists and engineer fifth edition. (2000). Serway and Beichner. Brooks/Cole.

4. 1998-2002) (soccer/broomball ball construction)

5. Marchant's School Sport Ltd .(1998) . (normal picture of ball)

6. (A soruce of information as well as a number of photographs.)

Special thanks:

Jake Kolipano, Mike Kudenov, Lauren Weiss, Shane Musgrave, Steve Houston, and Dustin Olson