@article{EJDE_2008__2008__a57,
     author = {Fan,  Xuanlong and Li,  Yongkun},
     title = {Positive periodic solutions of neutral functional differential equations with a parameter and impulse},
     journal = {Electronic journal of differential equations},
     year = {2008},
     volume = {2008},
     zbl = {1170.34347},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2008__2008__a57/}
}