Purity Relative to Classes of Finitely Presented Modules
  We investigate purities determined by classes of finitely presented modules including the correspondence between purities for left and right modules. We show some cases where purities determined by matrices of given sizes are different. Then we consider purities over finite-dimensional algebras, giving a general description of the relative pure injectives which we make completely explicit in the case of tame hereditary algebras. 
Akeel Ramadan Mehdi
math.RA