1. Designs and their Codes;Assmus,1992
2. Irreducible blocking sets in a symmetric design;Berardi;Bool. Un. Mat. Ital.,1987
3. L. Berardi, A note on 3-blocked designs, J. Combin. Des. (to appear).
4. Blocking sets of the known biplanes;Berardi;Rend. Mat. Appl.,1987
5. Constructing the biplanes of order four from six points;Berardi;Boll. Un. Mat. Ital. A,1988