@article{EJDE_2012__2012__a49,
     author = {Yang,  Chen and Zhai,  Chengbo},
     title = {Uniqueness of positive solutions for a fractional differential equation via a fixed point theorem of a sum operator},
     journal = {Electronic journal of differential equations},
     year = {2012},
     volume = {2012},
     zbl = {1261.34011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a49/}
}