1. Asami, T., Togari, H. and Ohashi, J. (1988). Analysis of movement patterns of referees during soccer matches. In Science and Football (edited by T. ReiiIy, A. Lees, K. Davids and W.J. Murphy), pp. 341-345. London: E & FN Spon.
2. Bangsbo, J. (1995). Fitness Training in Football: A Scientific Approach. Bagsvaerd, Denmark: HO+Storm.
3. Eissmann, H.J. (1996). The 23rd Man: Sports Medical Advice for Football Referees. Leipzig: Gersöne-Druck.
4. Reilly, T. (1996). Referees. In Science and Soccer (edited by T. Reilly), pp. 114-116. London: E & FN Spon.
5. Rohde, E. and Espersen, T. (1988). Work intensity during soccer training and match-play. In Science and Football (edited by T. Reilly, A. Lees, K. Davids and WJ. Murphy), pp. 68-75. London: E & FN Spon.