@Unpublished{K-theory/0512,
  author = 	 {{Pedro F. dos Santos and Paulo Lima-Filho}},
  title = 	 {{Quaternionic algebraic cycles and reality}},
  note = 	 {{Preprint, July 30, 2001, K-theory Preprint Archives, http://www.math.uiuc.edu/K-theory/0512/}}}
}