@Unpublished{K-theory/0681,
  author = 	 {{J.F. Jardine and Z. Luo}},
  title = 	 {{Higher order principal bundles}},
  note = 	 {{Preprint, February 7, 2004, K-theory Preprint Archives, http://www.math.uiuc.edu/K-theory/0681/}}}
}