modules.相关论文
In 1967, K. Koh showed that (Ⅰ)if a ring R contains n (n】1) left (right)zero divi-sors, then |R|≤n~2; (Ⅱ)if a ring R......
In this paper we introduce the notion of relative syzygy modules. We then study the extensionclosure of the category of ......