Achter, V. , Breuers, S. , Seifert, M. , Lang, U. , Götze, J. , Reuther, B. , Müller, P.. "Developing a Sustainable Educational Portal for the D-Grid Community". World Academy of Science, Engineering and Technology, Open Science Index 31, International Journal of Computer and Systems Engineering (2009), 3(7), 1823 - 1830.