4Lin Yi, Liu Sifeng. Several programming models with unascertained parameters and their application[J]. Journal of Multi-Criteria Decision Analysis. 1999,8(1):206～220.
5Liu Sifeng. On perron-frobenius theorem of grey nonnegative matrix[J]. The Journal of Grey System,1989,1(2):157～166.
6Liu Sifeng. The three axioms of buffer operator and their application[J]. The Journal of Grey System,1991,3(1):39～48.
7Liu Sifeng. Grey forecast of drought and inundation in henan province[J]. The Journal of Grey System. 1994, 6(4):279～288.
8Liu Sifeng. On measure of grey information[J]. The Journal of Grey System,1995,7(2):97～101.
9Liu Sifeng, Zhu Yongda. Grey-econometrics com-bined model[J]. The Journal of Grey System,1996,8(1):103～110.
10Liu Sifeng. Axiom on grey degree[J]. The Journal of Grey System,1996, 8(4):397～400.
