L. Maicher, and L. Garshol (Eds.) Leipzig, Fourth International Conference on Topic Maps Research and Applications, TMRA 2008, Leipziger Informatik-Verbund, (2008)
T. Syrjänen. Helsinki University of Technology, Faculty of Information and Natural Sciences, Department of Information and Computer Science, Espoo, Finland, Doctoral dissertation, TKK Dissertations in Information and Computer Science TKK-ICS-D12, (2009)