@article{EJDE_2009__2009__a47,
     author = {Xi,  Shouliang and Jia,  Mei and Ji,  Huipeng},
     title = {Multiple nonnegative solutions for second-order boundary-value problems with sign-changing nonlinearities},
     journal = {Electronic journal of differential equations},
     year = {2009},
     volume = {2009},
     zbl = {1176.34029},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2009__2009__a47/}
}