Alberto González-Cantos Aníbal Ollero Backing-Up Maneuvers of Autonomous Tractor-Trailer Vehicles using the Qualitative Theory of Nonlinear Dynamical Systems. 49-65 2009 28 I. J. Robotic Res. 1 http://dx.doi.org/10.1177/0278364908097588 db/journals/ijrr/ijrr28.html#Gonzalez-CantosO09