1. Seminormalità e singolarità ordinarie;Bombieri,1973
2. Continuous closure, axes closure, and natural closure;Epstein;Trans. Amer. Math. Soc.,2018
3. Tight closure, integral closure, and the Briançon-Skoda-theorem;Hochster;J. Amer. Math. Soc.,1990
4. Melvin Hochster, Craig Huneke, Tight closure in equal characteristic 0, 1999, in preparation.