1. Faculty of Business Administration and Economics, University of Paderborn, 33098 Paderborn, Germany;
2. Faculty of Computer Science, University of Koblenz, 56070 Koblenz, Germany;
3. Faculty of Business and Economics, University of Goettingen, 37073 Goettingen, Germany;
4. College of Business, Alfaisal University, Riyadh 11533, Kingdom of Saudi Arabia