1. Introduction to Commutative Algebra;Atiyah,1969
2. Hochschild homology criteria for smoothness;Avramov;Duke Math. J.,1992
3. BACH, A. Campillo, J. Guccione, J.J. Guccione, M.J. Redondo, A. Solotar, O. Villamayor, A Hochschild homology criterium for smoothness, Comment. Math. Helv. 69 (1994) 163–168.
4. D. Burghelea, M. Vigué, Cyclic homology of commutative algebras I, Lecture Notes in Mathematics, Vol. 1318, Springer, Berlin, 1988, pp. 51–72.
5. Homological coalgebra;Doi;J. Math. Soc. Japan,1981