中国科学院数学与系统科学研究院期刊网
On the Positive Solutions of a Kind of Neutral Equations with Positive and Negative Coeffcients
Xian Hua TANG,Jian She YU
Acta Mathematica Sinica, Chinese Series . 1999, (5): 795 -802 .  DOI: 10.12386/A1999sxxb0107