COMMUNICATIONS IN ALGEBRA, vol.46, no.10, pp.4480-4497, 2018 (SCI-Expanded)
In this article, we study the C4- and D4-modules in terms of perspective direct summands, providing new characterizations and results. Endomorphism rings of C4-modules and extensions of right C4-rings are also investigated. Decompositions of C4-modules with restricted ACC on direct summands and D4-modules with restricted DCC on direct summands are obtained.