@article{EJDE_2012__2012__a77,
     author = {Benterki,  Rebiha and Llibre,  Jaume},
     title = {Polynomial differential systems with explicit non-algebraic limit cycles},
     journal = {Electronic journal of differential equations},
     year = {2012},
     volume = {2012},
     zbl = {1261.34031},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a77/}
}