1. Algebraic Combinatorics I, Association Schemes;Bannai,1984
2. Distance-regular graphs;Brouwer,1989
3. The theory of non-symmetric association schemes with three classes;Claasen,1986
4. Cyclotomy and association schemes;Claasen,1989
5. A field-like property of finite rings;Claasen;Indag. Math.,1992