We prove the following results for a ring R.(a) If C is a class of right R-modules closed under
direct summands and isomorphisms, then every right R-module has an epic C-envelope if …

It is a well-known result that the direct sum of any family of injective modules over a
Noetherian ring is injective. Conversely, if A is a ring with the property that the direct sum of …

Throughout this paper R will denote a ring with idenity element and M a unitary right module
over R. An R-module M is said to be direct injective if and only if given direct summand N of …

We investigate when the direct sum of semi-projective modules is semi-projective. It is
proved that if R is a right Ore domain with right quotient division ring Q≠ R and X is a free …

Classically, there has been, for obvious reasons, an intimate relation between the concepts"
rings of quotients" and" divisible modules". Recently, however, their generalizations have …

It is proved that A is a right distributive ring if and only if all quasiinjective right A-modules are
Bezout left modules over their endomorphism rings if and only if for any quasiinjective right A …

!THE $\aleph_1$-PRODUCT OF DG-INJECTIVE COMPLEXES Page 1 Proceedings of the
Edinburgh Mathematical Society (2006) 49, 257–266 c DOI:10.1017/S0013091505000143 …

DUALITY THEORY FOR QUASI-INJECTIVE MODULES JM Zelmanowitz Department of
Mathematics University of California, Santa Barbara, C Page 1 DUALITY THEORY FOR …

In [3] an attempt was made at proving the following result:(A) An N-module M over a dg near-
ring is injective if and only if for each right ideal u of N and each N-homomorphism f: u→ M …