@article {2002, title = {Geometry of Jacobi curves II}, journal = {J. Dynam. Control Systems 8 (2002), no. 2, 167--215}, number = {SISSA;18/2002/M}, year = {2002}, publisher = {SISSA Library}, doi = {10.1023/A:1015317426164}, url = {http://hdl.handle.net/1963/1589}, author = {Andrei A. Agrachev and Igor Zelenko} }