@article{article381caa30,
title   = {Covering space for monotonic homotopy of trajectories of control systems},
author = {Colonius, Fritz and Kizil, Eyup and San Martin, Luiz A B},
year = {2005},
doi = {10.1016/j.jde.2005.02.021},
journal   = {Journal of Differential Equations}
}