A ring is called quasi-Frobenius, briefly QF, if it is right (or left) Artinian and right (or left) self-
injective. A ring R is said to be right (left) perfect if every right (left)/?-module has a projective …

In (l), rings whose cyclic left R-modules not isomorphic to R are injective (called left PCI-
rings) are considered. A left R-module M is called CF-injective if for any finitely generated left …

It is well-known that a right self-injective, left go-injective regular ring is directly finite, and
then unit-regular (cf.[2, Theorem 9.29].) Also, it is proved in [3, Theorem 1.8] that a right go …

In this paper, we introduce and study the dual notion of simple-direct-injective modules.
Namely, a right R-module M is called simple-direct-projective if, whenever A and B are …

We studied almost relative projective modules and almost relative injective modules in [3, 6,
7]. In this short note we define a new module, an almost projective (resp. almost injective) …

We say that a ring K is (right) split by a subring A provided that A is an (right) A-module direct
summand of K. Then K is said to be a split extension of A. By a theorem of Azumaya [lJ, a …

One of the main results of this paper is the characterization of left FP-injective rings as rings
over which every finitely presented right module is torsionless. The necessity of the …

A ring R is called right principally injective if every R-homomorphism from a principal right
ideal to R is left multiplication by an element of R. In this paper various properties of these …

Rings all of whose right ideals are automorphism-invariant are called right a-rings. In the
present paper, we study rings having the property that every right cyclic module is dual …

The following results are extended fromP-injectiverings to AP-injective rings:(1) R is left self-
injective regular ifand only if R is a right (resp. left) AP-injective ring such that forevery nitely …