@InCollection{RCA:11,
author = "Bachmann, O.",
title = "Effective Simplification of CR expressions",
year = "1997",
month = "January",
  booktitle = "Reports On Computer Algebra",
  publisher = "Centre for Computer Algebra, University of Kaiserslautern",
  number = 11,
  note ="Online available at http://www.mathematik.uni-kl.de/~zca"
}