1. Perfect codes and distance-transitive graphs;Biggs,1974
2. Perfect codes in graphs;Biggs;J. Combinatorial Theory (B),1973
3. Circle geometry in higher dimensions, II;Bruck;Geometriœ Dedicata,1973
4. P. J. Cameron, J. A. Thas, and S. E. Payne, Polarities of generalized hexagons and perfect codes, Geometriœ Dedicata, to appear.
5. An algebraic approach to the association schemes of coding theory;Delsarte;Philips Res. Rep. Suppl.,1973