5MIAO ZHENGKE(Department of Mathematics, Nanjing University, Nanjing 210093, China.)(Department of Mathematics, Xuzhou Normal University, Xuzhou 221009, China.) ZHANG KEMIN(Department of Mathematics, Nanjing University, Nanjing 210093, China.).THE SECOND EXPONENT SET OF PRIMITIVE DIGRAPHS[J].Chinese Annals of Mathematics,Series B,2000,21(2):233-236. 被引量:8