1. Quadratic forms over semi-local rings;Baeza,1978
2. Algèbre;Bourbaki,1981
3. Algèbre Commutative;Bourbaki,1961
4. Galois theory and Cohomology of commutative rings;Chase;Mem. Amer. Math. Soc.,1965
5. The group of unramified Kummer extensions of prime degree;Childs,1977