摘要
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 contains n (n】1)left (right)zero divisors, and it has an identity and |R|=n^2, then n is a power of a prime p, and every minimal right ideal I of R necessarily satisfies I^2=0. In fact, if a ring R contains one-sided zero divisors, then
