中国科学院数学与系统科学研究院期刊网
The Solutions for Semipositone (k,n-k) Conjugate Boundary Value Problems
Hua SU, Li Shan LIU
Acta Mathematica Sinica, Chinese Series . 2015, (2): 261 -270 .  DOI: 10.12386/A2015sxxb0026