中国科学院数学与系统科学研究院期刊网
Oscillation and Nonoscillation of Solutions of Second Order Damped Elliptic Differential Equations
Zhi Ting XU
Acta Mathematica Sinica, Chinese Series . 2004, (6): 1099 -110 .  DOI: 10.12386/A2004sxxb0136