S. Blümling, and N. Reithinger. Proceedings of DeLFI Workshops 2015, co-located with 13th e-Learning Conference of the German Computer Society (DeLFI-15), Munich, Germany, volume 1443 of CEUR Workshop Proceedings, page 10--18. RWTH Aachen, Sun SITE Central Europe, (2015)
F. Gruber. Digital Product and Process Development Systems, volume 411 of IFIP Advances in Information and Communication Technology, Springer, Heidelberg, (2013)
H. Hirsch-Kreinsen. Soziologisches Arbeitspapier, 38. Technische Universität Dortmund, Wirtschafts- und Sozialwissenschaftliche Fakultät, Dortmund, (January 2014)