中国科学院数学与系统科学研究院期刊网
Symmetric Positive Solutions to a Fourth-Order Nonlinear Differential Equation with Nonlocal Boundary Conditions
Yong Ping SUN
Acta Mathematica Sinica, Chinese Series . 2007, (3): 547 -556 .  DOI: 10.12386/A2007sxxb0065