中国科学院数学与系统科学研究院期刊网
Multiple Positive Solutions for Semi-positone m-point Boundary Value Problems
Cheng-bo Zhai, Cheng Yang
Acta Mathematicae Applicatae Sinica(English Series) . 2011, (3): 419 -426 .  DOI: 10.1007/s10255-009-6180-3