References
- Henderson , J. and Wang , H. 1997 . Positive solutions for nonlinear eigenvalue problems . J. Math. Anal. Appl , 208 : 252 – 259 .
- Krasnosel'skii , M.A. 1964 . Positive Solutions of Operator Equations , Groningen : Noordhoff .
- Wang , H. 1994 . On the existence of positive solutions for semilinear elliptic equation in the annulus . Differential Equations , 109 : 1 – 7 .
- Ruyun , M. , Jihui , Z. and Shengmao , F. 1997 . The method of lower and upper solutions for fourth-order two-point boundary value problems . J. Math. Anal. Appl , 215 : 415 – 422 .
- Ruyun , M. and Haiyan , W. 1995 . On the existence of positive solutions of fourth-order ordinary differential equations . Appl. Anal , 59 : 225 – 231 .