@article{EJDE_2007__2007__a83,
     author = {Yang,  Dandan and Zhu,  Hongbo and Bai,  Chuanzhi},
     title = {Positive solutions for semipositone fourth-order two-point boundary value problems},
     journal = {Electronic journal of differential equations},
     year = {2007},
     volume = {2007},
     zbl = {1118.34019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2007__2007__a83/}
}