@article {2001,
	title = {Morse properties for the minimum time function on 2-D manifolds},
	journal = {J. Dynam. Control Systems 7 (2001), no. 3, 385--423},
	number = {SISSA;84/00/M},
	year = {2001},
	publisher = {SISSA Library},
	doi = {10.1023/A:1013190914234},
	url = {http://hdl.handle.net/1963/1541},
	author = {Ugo Boscain and Benedetto Piccoli}
}
