4WANG Yanming & WEI HuaquanLingnan College and School of Mathematics, Zhongshan University, Guangzhou 510275, China,School of Mathematics, Zhongshan University, Guangzhou 510275, China,Department of Mathematics, Guangxi Teacher’s College, Nanning 530001, China.On a problem of Skiba from the Kourovka Notebook[J].Science China Mathematics,2004,47(1):96-103. 被引量:1