@Unpublished{K-theory/0312,
  author = 	 {{A. J. Berrick and Carles Casacuberta}},
  title = 	 {{A universal space for plus-constructions}},
  note = 	 {{Preprint, November 16, 1998, K-theory Preprint Archives, http://www.math.uiuc.edu/K-theory/0312/}}}
}