@article {2006, title = {Classification of stable time-optimal controls on 2-manifolds}, journal = {J. Math. Sci. 135 (2006) 3109-3124}, number = {SISSA;20/2004/M}, year = {2006}, doi = {10.1007/s10958-006-0148-0}, url = {http://hdl.handle.net/1963/2196}, author = {Ugo Boscain and Igor Nikolaev and Benedetto Piccoli} }