1. The Lefschetz theorem on hyperplane sections;Andreotti;Ann. of Math. (2),1959
2. Projective Geometry and Formal Geometry;Bădescu,2004
3. Algebraic Surfaces;Bădescu,2001
4. Anticanonical models of ruled surfaces;Bădescu;Ann. Univ. Ferrara,1983
5. Una osservazione sulle varietà razionali normali;Beltrametti;Boll. Unione Mat. Ital. (4),1973