中国科学院数学与系统科学研究院期刊网
A Necessary and Sufficient Condition for the Existence of Positive Solutions of Fourth Order Singular Superlinear Differential Equations
Zeng Qin ZHAO
Acta Mathematica Sinica, Chinese Series . 2007, (6): 1425 -143 .  DOI: 10.12386/A2007sxxb0167