M. Maaser, S. Ortmann, и P. Langendörfer. WEBIST (Selected Papers), том 8 из Lecture Notes in Business Information Processing, стр. 85-97. Springer, (2007)
M. Rychetsky, S. Ortmann, и M. Glesner. NC, стр. 603-609. ICSC Academic Press, International Computer Science Conventions, Canada / Switzerland, (1998)
S. Ortmann, M. Rychetsky, и M. Glesner. NC, стр. 995-1001. ICSC Academic Press, International Computer Science Conventions, Canada / Switzerland, (1998)