@Unpublished{K-theory/0452,
  author = 	 {{Igor Nikolaev}},
  title = 	 {{Noncommutative rings and characteristic classes of foliations}},
  note = 	 {{Preprint, October 4, 2000, K-theory Preprint Archives, http://www.math.uiuc.edu/K-theory/0452/}}}
}