1. Lecture Notes in Artificial Intelligence;D. Hales,2000
2. Hales, D.:Tag Based Cooperation in Artificial Societies. Unpublished Ph.D. Thesis, Department of Computer Science, University of Essex (2001)
3. CPM Working Paper;D. Hales,2002
4. CPM Working Paper;D. Hales,2002
5. CPM Working Paper;D. Hales,2002