@InCollection{ brockett81control,
  author = 	 {Roger W. Brockett},
  title = 	 {Control Theory and Singular Riemannian Geometry},
  booktitle = 	 {New Directions in Applied Mathematics},
  pages = 	 {11--27},
  publisher = {Springer},
  year = 	 {1981},
  editor = 	 {P. J. Hilton and G. S. Young},
  address = 	 {New York}
}