We characterize semiperfect modules? semiperfect rings, and perfect rings using locally
projective covers and generalized locally projective covers, where locally projective …

The notion of generalized projective covers Is Introduced to give a natural generalization of
a theorem of Bass on perfect rings. Moreover, In terms of this notion, some characterizations …

In Bican et al., it is proved that all modules over an arbitrary ring have flat covers. In this
article, we shall study rings over which flat covers of finitely generated modules are …

If R is a ring without zero divisors then it is shown that any torsion-free quasi-projective left R-
module A is projective provided A is finitely generated or A is “big”. It is proved that the …

Zhou defined\delta-semiperfect rings as a proper generalization of semiperfect rings. The
purpose of this paper is to discuss relative notions of supplemented modules and to show …

Characterization of Rings Using Quasiprojective Modules. II Page 1 PROCEEDINGS OF THE
AMERICAN MATHEMATICAL SOCIETY Volume 28, Number 2, May 1971 CHARACTERIZATION …

Recently,]~. DE ROBERT has considered the dual concepts of relative projectivity and
relative injectivity that extend the notions of quasi-projective and quasi-injective modules …

In this paper, principally supplemented modules are defined as generalizations of lifting,
principally lifting and supplemented modules. Several properties of these modules are …

Weakening the notion of R-projectivity, a right R-module M is called max-projective provided
that each homomorphism f: M→ R/I, where I is any maximal right ideal, factors through the …

For a ring R and a right R-module M, a submodule N of M is said to be δ-small in M if,
whenever N+ X= M with M/X singular, we have X= M. If there exists an epimorphism p: P→ M …