1. ARTZY, R.: Pascal's theorem on an oval. Amer. Math. Monthly75 (1968), 143?146
2. BUEKENHOUT, F.: Etude intrins�que des ovales. Rendic. Mat.25(5) (1966), 333?393
3. CHEROWITZO, W.: On the Extension of Pre-oval Configurations. Dissertation, Columbia University 1983
4. CONTI, G.: Piani proiettivi dotati di un'ovale pascaliana. Boll. Un. Mat. Ital.14(4) (1975), 143?153
5. DEMBOWSKI, P.: Finite Geometries. Springer-Verlag, Berlin 1968