@article{EJDE_1998__1998__a8,
     author = {Toni,  B.},
     title = {Branching of periodic orbits from {Kukles} isochrones},
     journal = {Electronic journal of differential equations},
     year = {1998},
     volume = {1998},
     zbl = {0899.34027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1998__1998__a8/}
}