Beyond Totally Reflexive Modules and Back
  Starting from the notion of totally reflexive modules, we survey the theory of Gorenstein homological dimensions for modules over commutative rings. The account includes the theory's connections with relative homological algebra and with studies of local ring homomorphisms. It ends close to the starting point: with a characterization of Gorenstein rings in terms of total acyclicity of complexes. 
Lars Winther Christensen, Hans-Bj{\o}rn Foxby, and Henrik Holm