Mathematical Journal of Okayama University volume63 issue1
Department of Mathematics Education Osaka Kyoiku University
In  M. Harada studied a left artinian ring R such that every non-small left R-module contains a non-zero injective submodule. And in  K. Oshiro called the ring a left Harada ring (abbreviated left H-ring). We can see many results on left Harada rings in  and many equivalent conditions in [4, Theorem B]. In this paper, to characterize two-sided Harada rings, we intruduce new concepts “co-H-sequence” and “H-epimorphism” and study them.
Mathematics Subject Classiﬁcation. 16P20.