@article{EJDE_2006__2006__a164,
     author = {Zhang,  Shuqin},
     title = {Positive solutions for boundary-value problems of nonlinear fractional differential equations},
     journal = {Electronic journal of differential equations},
     year = {2006},
     volume = {2006},
     zbl = {1096.34016},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2006__2006__a164/}
}