1. Artin, M., Verdier, J.-L. Reflexive modules over rational double points. Math. Ann. 270(1), 79–82 (1985). MR 769609
2. Auslander, M.: Isolated singularities and existence of almost split sequences. Representation Theory, II (Ottawa, Ont., 1984). Lecture Notes in Mathematics, vol. 1178, pp. 194–242. Springer, Berlin (1986). MR 842486
3. Auslander, M.: Rational singularities and almost split sequences. Trans. Amer. Math. Soc. 293(2), 511–531 (1986). MR 816307
4. Avramov, L.L.: Infinite free resolutions. Six Lectures on Commutative Algebra (Bellaterra, 1996). Progress in Mathematics, vol. 166, pp. 1–118. Birkhäuser, Basel (1998). MR 1648664
5. Bass, H.: Torsion free and projective modules. Trans. Amer. Math. Soc. 102, 319–327 (1962). MR 0140542