1. Harper, T., 2007. Robotic simulation of golf swings. PhD thesis, Loughborough University, UK.
2. Neilson, P., Jones, R., Kerr, D., and Sumter, C., 2004. An automated system for the measurement of soccer ball flight characteristics. The Engineering of Sport, 5,(2), pp. 180–6.
3. Neilson, P., Jones, R., Kerr, D., and Sumter, C., 2004. An image recognition system for the measurement of soccer ball spin characteristics. Institute of physics publishing, Measurement Science and Technology, 15, pp. 2239–47.
4. Rhodes, D., R., 1959. Introduction to monopoles. McGraw-Hill.
5. Sporting Goods Manufacturing Association, (SGMA)., 2007. Manufacturers sales by category report, US wholesale value of annual manufacturers’ shipments ($million).