C. Menzel, I. Thomas, C. Wolter, and C. Meinel. Proc. Stuttgarter Softwaretechnik Forum (SSF), page 41-53. Stuttgart, Fraunhofer IRB-Verlag, (November 2007)ISBN 978-3-8167-7493-8.
M. Quasthoff, H. Sack, and C. Meinel. n Proc. of the 2007 IEEE / WIC /ACM Int. Conf. on Web Intelligence (WI 2007), (2007)location=Silicon Valley, date=2007.