@article{articlea57471eb,
title   = {Unstable dimension variability and codimension-one bifurcations of two-dimensional maps},
author = {Viana, Ricardo L and Barbosa, José R R and Grebogi, Celso},
year = {2004},
doi = {10.1016/j.physleta.2003.12.049},
journal   = {Physics Letters A}
}