1. A duality for torsion free modules of finite rank over a discrete valuation ring;Arnold,1972
2. Representation theory of Artin algebras III—Almost split sequences;Auslander;Comm. Algebra,1975
3. Torsion free rings, Ill.;Beaumont;J. Math.,1961
4. Commutative Algebra;Bourbaki,1972
5. Indecomposable representations of graphs and algebras;Dlab;Mem. Amer. Math. Soc.,1976