Markus Helfert and Gregor Zellner, “An Attempt to Design and Model Activities for Student retention,” Proceedings of the 6th International Business Information Management Association (IBIMA), ISBN: 978-0-9753393-5-0, 19- 21 June 2006, Bonn, Germany, p.176-178.
Markus Helfert, Pamela Henry, Susanne Leist and Gregor Zellner, “Healthcare performance indicators -Preview of frameworks and an approach for healthcare process-development,” Proceedings of the 4th International Business Information Management Association (IBIMA), ISBN: 978-0-9753393-3-6, 5- 7 July 2005, Lisbon, Portugal, p.371-378.