@article {2011,
	title = {The geometry of Maximum Principle},
	journal = {Proceedings of the Steklov Institute of mathematics. vol. 273 (2011), page: 5-27 ; ISSN: 0081-5438},
	number = {Proceedings of the Steklov Institute of mathematics;v.273},
	year = {2011},
	abstract = {An invariant formulation of the maximum principle in optimal control is presented, and some second-order invariants are discussed.},
	url = {http://hdl.handle.net/1963/6456},
	author = {Andrei A. Agrachev and Revaz Gamkrelidze}
}
