@article{JEMS_2011_13_6_a1,
     author = {Rafael Ortega and Francisco R. Ruiz del Portal},
     title = {Attractors with vanishing rotation number},
     journal = {Journal of the European Mathematical Society},
     pages = {1569--1590},
     publisher = {mathdoc},
     volume = {13},
     number = {6},
     year = {2011},
     doi = {10.4171/jems/288},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/jems/288/}
}